Case Studies

A Collection of the Odd, Unusual and Interesting Found While Servicing Our Client Vehicles.

Originally intended as a showcase for customers of our workshop and staff’s abilities, this page has evolved in an interesting and informative teaching tool, and one of the most popular pages on our site!

By nature, these are rather extreme examples of failures, and not what we typically find during service. Our goal at Atlantic Motorcar is to prevent these from happening to you and your car. But rest assured, if we can fix these challenges, regular maintenance is breeze!

We like to call this our “YES WE CAN!” page. You can also view many of these concerns on our Facebook page. Each photo can be enlarged by clicking on it.

Automotive Air Conditioning Service – Myths, Magic and Mistakes

Case Studies

A Little Background
Air conditioning is one of those systems that has evolved over the years, and with it some old myths that have died hard. The days of the R12 (Freon) systems are nearly 30 years in the past, but I still here from time to time, the same myths and mistakes, chief among those is the “topping off” concept. This can be downright dangerous, if you buy the the flammable gas that is often sold in small quantities rather than the proper refrigerant.

The other thing I hear about is A/C  compressor failures, with no explainable cause. There are two general types of compressor failures, the first being electrical, which is a small subset, and other being mechanical. Almost every compressor failure occurs as a result of mechanical wear or damage, and almost always it relates to a lubrication failure caused by undercharging, or systems run low on refrigerant.

An Ounce of Prevention
I’ve authored this simple case study to explain how A/C has evolved from the “early days”, and the importance of thinking of preventive maintenance on the A/C system to prevent premature failures. We often think of A/C as system requiring no maintenance until it doesn’t work. That’s akin to ignoring brushing your teeth until you get a toothache, by then it’s often too late. You read how some small loss of refrigerant from a sealed A/C system is not only normal, but should be expected.

Myth 1 – “Topping Up” A/C Systems
The very first myth that needs to be addressed is “topping up” your system. Did you know that if your system is 10% low, you will lose 40% of your oiling capability to your A/C Compressor? You won’t experience lack of cooling until you have lost 40% of your refrigerant. During that time, from -10% to -40% loss of charge, you are doing damage to your compressor.

Problem is, your compressor does not have a sump like your engine does, it relies on the proper volume of refrigerant in the system to push the refrigerant oil back to the compressor. The compressor is one of the most costly parts in your vehicle’s climate control system, so therefore preventing problems should be the focus. The number one reason for compressor problems is caused by lubrication failures, most often the lack of refrigerant to move the oil around the system, in other words, an undercharged or leaking system.

Mistake – Why “Topping Up” Really Doesn’t Work
The problem with topping up your system is you don’t know how much refrigerant is in your system to add to it. There is no “dip stick” to indicate refrigerant charge. Back in the “old days“, vehicles had what were termed “sight glasses“, a small clear viewing port, often on the receiver dryer, that allowed one to see into the system, and to charge until no air bubbles were present. The sight glass went the way of the old R12 refrigerent systems, back in 1994.

Yet the myth persists, nearly 30 years later, that one can just “top off” the A/C system, like you top off brake fluid. Problem is, brake fluid is in a translucent container, refrigerant is not, you can’t see through the metal pipes and lines. When you add refrigerant to your system that is blowing warm you can increase the charge until the system starts to blow cold, but you may still be in the -10% to -40% low refrigerant range, which is still doing damage to your compressor by not providing proper lubrication to the system.

The Right Way
The only proper way to service your vehicle air conditioning is to recover the system, pull a vacuum to remove contaminants such as air and moisture, install refrigerant oil to lubricate the compressor, and then install the factory refrigerant charge as specified by the manufacturer. This requires a professional A/C service machine, which costs several thousand dollars, and some specialized equipment. The good news is that most A/C recharge services cost under $300, far less than a compressor replacement.

Little Cans Make A Big Difference

  • The current automotive refrigerant (R-134a) is a highly potent greenhouse gas.

  • Just the gas contained in one single 12-ounce container is equivalent to the carbon dioxide (CO2) emissions from burning 150 gallons of gasoline!

  • The gas from two 12-ounce containers, if released into the atmosphere, will cause the same global warming pollution as driving all the way across the country diagonally, from Los Angeles to New York.

Myth 2 – “Magic” Parts Store Recharge Cans – Buying Yourself A Can Of Trouble
The second myth is those “little cans of refrigerant” that are being sold at do it yourself parts stores. Federal Law states you can not sell refrigerant in containers that contain less than 22 pounds (10kg). If you are purchasing a container that has 6-12 ounces of “refrigerant” in it, this is often NOT R134a (refrigerant) which is required for your vehicle. What you are buying is called a Hydrocarbon, also known as a propane and butane mixture.

The way you can tell is to look at the labeling on the container, it will show the explosive and flammable symbol. R134a will ONLY show the compressed gas symbol on the label. R134a is not flammable or explosive, and is specified by the vehicle manufacturer for your vehicle. R134a and all proper refrigerants require technicians to be Federally certified to handle them. They are not available to be purchased without the proper certification.


A/C Fact – It’s Always Working – Even In The Winter

Here’s a surprising fact, your vehicle’s A/C never takes a break, not even in the winter. In fact your vehicles air conditioning system runs whenever you turn on the Defrost mode, and often runs when in the automatic mode.

The climate control system uses the a/c as it is designed to engage and act as a dehumidifier to remove the moisture from the air entering your vehicle to aid in removing moisture (fogging) from your windows.

You will notice vehicles with working air conditioning that the side and back windows are always clear. Vehicles without air conditioning or needing A/C repairs will have steamed up side and back windows which continually need wiping to clear.

Waiting Costs You Money
If your A/C system is not working 100% at the end of the summer season and you think you will get it fixed next year, do not put it off or you will do damage to your compressor. Remember, when you turn on the Defrost Mode, the compressor is engaged. With a low refrigerant charge over the winter months, you’re not getting the refrigerant oil back to the compressor which is damaging it all winter season that will lead to costly repairs in the spring time.

A/C Fact – A/C Service Is Normal – Think Every 3-5 Years
The Society of Automotive Engineers (SAE) designed the A/C fittings that are on your vehicle. These fittings have a SAE acceptable leakage rate of 1/4 ounce of refrigerant per year per fitting. That does not sound like a lot, but the average vehicle has 8 fittings. This means that you are losing 2 ounces of refrigerant per year.

So now that we know that you are are losing 2 ounces of refrigerant per year, and A/C service is just part of a proper maintenance schedule. It is recommended that you service your air conditioning every 3-5 years. This will ensure that your compressor is never “starving” for oil. The older vehicles used to have systems that held upwards of 36 ounces of refrigerant. Today’s vehicles have much smaller systems that require as little as 15 ounces of refrigerant. The need to service your air conditioning has become much more important with these reduced capacities or system damage will occur.

Our Goal For You and Your Car
Our goal is to save you money, not spend it.
This is why each and every car that we service gets a free Courtesy Maintenance Inspection during its first visit.

We aim to let you know about the small problems before they become big.
Right now we have a number of customer cars with well over 200,000 miles, and several approaching 300,000!
And these cars are not just limping along – most look and drive pretty much the way they came out of the showroom.

Proper maintenance is an investment in the life of your vehicle.
Knowing, not just doing, but actually knowing and understanding the difference, makes all the difference.
Be sure your car is properly loved, our professionals will attend to both you and your car’s needs.

Atlantic Motorcar…Extraordinary Service for Extraordinary Cars, just a phone call away, (207) 882-9969!

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The Proper Use Of The Air Conditioning Air Recirculation Button In Your Vehicle

Case Studies

The Proper Use Of The Air Recirculation Button In Your Vehicle
When the weather heats up, and it’s time to turn on your vehicle air-conditioning, there’s one button you may not know how to use. Have you seen the button in your car that shows an arrow going in a circle? That’s the air-recirculation button. Although some drivers know what it’s called, many don’t know what it’s for! If you’ve ever wondered why it’s there and what it does – read on; you’ll be glad you did!

What Does The Air Recirculation Button Do?
The air recirculation button effectively cuts off the outside air to the inside of the car, ‘recirculating’ air inside your vehicle.
What the air-recirculation button is used for:

  • Boosting your AC to help your cabin get as cold as possible as quickly as possible
  • Stopping pollution & exhaust fumes i.e., in a city center traffic jam, entering your cabin
  • Reducing pollen when driving if you suffer from hayfever
  • Stopping strong outdoor odors entering your car

The Benefits Of The Air Recirculation Button

  • The air-recirculation function ensures your AC works to the optimum level, allowing your vehicle to get as cold as possible as quickly as possible.
  • It helps stop pollution, smells, and pollen from entering your cabin
  • It helps keep your air-filter cleaner for longer
  • It reduces strain on your AC system
  • It helps reduce fuel consumption by assisting the AC system

Some new cars do not have an air-recirculation button. This is because modern vehicles are often equipped with sensors that monitor the cabin air and moisture levels, adjusting the “air circulation” automatically.

When To Use The Air Recirculation Button

  • When using AC, unless the system becomes too cold, use it to quickly cool down your vehicle
  • In summer & hot weather
  • In dense traffic, to stop pollution from entering the cabin

Extreme Weather
If you’re driving in a heatwave, you should turn on your AC & your air-recirculation ON to ensure your air-con gets as cold as possible as quickly as possible.

If you don’t switch the air-recirculation button on, your air-conditioning will constantly cool warm air from outside your vehicle, and will have to work much harder, putting more stress on the blower & air compressor.

The system works by recirculating the cool air you get from your A/C when you first turn it on. The longer it’s on, the cooler your vehicle will get! If you don’t use it, the car will use the air from the outside that is much warmer, and your A/C will work harder and continuously to cool the hot air.

If your AC has to work harder, you’ll increase fuel consumption, and your cabin won’t reach its optimum level of coldness from the air-con system. You will also be putting undue wear and tear on your A/C compressor.

When Not To Use Air-Recirculation
In winter and cold weather. Generally, when its cold outside, ensure the recirculation button is switched off! The air-recirculation button is best to use alongside your AC during warm weather. It doesn’t benefit much during cooler weather and can even be detrimental.

Some drivers think it makes sense not to have “all that cold air coming in” if they use heaters in winter. However, in reality, it’s best to keep it switched off. The standard “fresh air” mode forces the outside air through your heater core, so it’s nice and toasty before it reaches you, and your windows will de-fog a lot quicker and stay that way while you drive.

Disadvantages Of The Air Recirculation Button
The main downside of the air-recirculation button is that it traps humidity inside the car, which results in misted windscreens, especially when the air is cold outside and in wet weather.

  • It can cause your windscreen to mist up
  • It can trap humidity in the cabin
  • If your vehicle is fully loaded with passengers, it can cause it to be stuffy and may make you drowsy

Our Goal For You and Your Car
Our goal is to save you money, not spend it.
This is why each and every car that we service gets a free Courtesy Maintenance Inspection during its first visit.

We aim to let you know about the small problems before they become big.
Right now we have a number of customer cars with well over 200,000 miles, and several approaching 300,000!
And these cars are not just limping along – most look and drive pretty much the way they came out of the showroom.

Proper maintenance is an investment in the life of your vehicle.
Knowing, not just doing, but actually knowing and understanding the difference, makes all the difference.
Be sure your car is properly loved, our professionals will attend to both you and your car’s needs.

Atlantic Motorcar…Extraordinary Service for Extraordinary Cars, just a phone call away, (207) 882-9969!

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Keeping Your Cool – Air Conditioning (A/C) Recharge System Service Process and Costs

Case Studies

Anticipated Service Cost
If your car’s AC system efficiently drops and is no longer cooling or cooling effectively or has a flashing warning light, it may be running low on refrigerant. Pending finding no gross leaks, it may be as simple as a recharge. This isn’t a costly repair and likely won’t need to be done before you hit the 60,000 to 100,000-mile mark, so any car for five years or older will likely need this done at least once.

For most cars, an AC recharge will cost between $200 to $300, depending on the amount of refrigerant needed (larger vehicles use more refrigerant), including the addition of UV leak detection dye. It’s a straightforward procedure, but it can take a while to check everything out and ensure no further damage.

When to Get an AC Recharge Done?
It’s important to have your AC system recharged, don’t neglect an inoperative system. You can run it for a very short while before there is any serious damage, but you should take care of this problem sooner rather than later. Over time, the lack of refrigerant will put extra pressure on the compressor and other parts of the AC system, making them work harder; plus, any moisture which has entered the system can cause them to break down and require extensive repairs and replacement.

The best way to know if your system needs a recharge is to pay attention to its operation. You may notice that your system isn’t working as well as it should. It may have trouble producing cold air or make weird noises or overheat. These are signs that you need to have some inspection or service needs to be done.

What Is A Recharge System Service
Your AC system runs on a refrigerant. The refrigerant removes moisture from the inside of the car and deposits it to the outside. So you feel comfortable. But over time, the refrigerant will run out. It can escape through normal seepage. Also, major leaks or component failures can deprive the refrigerant. Once the refrigerant is low, the AC will no longer function properly.

Without the right refrigerant levels, your system can overheat and experience pressure that can damage the other components of the AC system. An AC recharge means checking the current pressure levels in the system and recharging it to get it to where it needs to be. This allows everything to operate smoothly, last longer, and produce cooler air.

What Is Done During AC Recharge Service
The technician will want to check for the source of the problem first. If you have a concern about some issue with your AC, we will perform a thorough check of the system to ensure that by recharging your unit, we are taking care of all the problems. You don’t want to pay for a recharge and then find out later that you have a refrigerant leak!

Once the technician sees that the system needs a recharge, he will evacuate all the refrigerant from the system using a coolant recovery machine. Once the parts have been evacuated, he will replace them and remove all the air from the system. The new refrigerant will be installed, and any damaged or worn seals must be replaced. If the unit leaks, one or more seals or hoses are usually at fault. We use a UV Dye test to check for current and future leaks.

UV Leak Detection
As many refrigerant leaks are often not detected until the vehicle has been in service for some time, we have chosen the UV Dye method as the most accurate and cost-effective available.

There are three common ways of finding leaks in the system:
1. Visual. If the leak is very obvious, we will see it with no help.
2. Use of a special UV flashlight and goggles
3. Gas/Refrigerant Leak detector.

This can only be done if the system has enough refrigerant & oil/dye in it to detect a leak, which is why this service must be performed first to determine the source of failure. This test will help us find the largest leak, it is possible that other (smaller) leaks will show up after a larger leak is repaired.

The customer must return at the first sign of loss of cold air; if the system runs out again and rain washes the dye away, this process must be re-done at the customer’s expense. Refrigerant is a greenhouse gas, and it is illegal to vent it out into the atmosphere. Therefore, we are not allowed to knowingly recharge a leaking A/C system.

Benefits of AC Repair
By recharging your AC unit, you will enjoy a system that works more efficiently and lasts longer. The air it produces will be colder, and you will protect the rest of your AC system and the surrounding car parts from overheating and other types of damage. You also enjoy the benefits of an AC system that works like it should every time, providing cold air when needed and keeping your car comfortable.

How We Can Help You
The Service Team here at Atlantic Motorcar is well experienced in this issue and others; with over 35 years of European auto specialization, serving clients from the areas of New England, we are familiar with the needs of the special service of your auto.

As Maine’s leading European auto specialists, we provide expert-quality services at a fair rate than nearby dealerships and specialty shops. If you’re experiencing any of the above-mentioned symptoms in your auto, please call us immediately; we can usually see your car the same day! At Atlantic Motorcar, we’ve developed some very specific procedures and tooling, combined with our expert technicians, to make this otherwise onerous repair a snap.

Finally
Questions or if we can help with service on your Audi, BMW, Mercedes, Sprinter, Honda, Infiniti, Lexus, Mini Cooper, Porsche, Volvo, and VW, don’t hesitate to get in touch with us. Our team of Service Specialists is here to help, for even the newest autos! (207) 882-9969.

Knowing, not just “doing,” that’s the Atlantic Motorcar Center way.
Thanks!

Warmly,
The Atlantic Motorcar Center Service Team

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Audi, Porsche and VW 2.0 TSI Engines – Rear Main Seal Oil Leaks And Proper Correction

Case Studies

Vehicles Affected
The Audi and VW 2.0L TFSI, TSI, and FSI engines have been around for almost 15 years. During that time, Audi/VW made endless revisions and updates to the hardware and software.

You may have read of the problems with the leaking rear main crankshaft seal on the Audi and VW 2.0 TSI engines. This is a common pattern failure with 2009-2012 Volkswagen Tiguans. We say 2009-2012 VW Tiguans, but the issue can occur on any 2.0TSI Volkswagen, Audi or Porsche (2014+ Macan) using this seal design.

As with all cars, the Rear Main Seal is located between the engine’s crankshaft and the flywheel, which means the transmission must be removed to replace this part. This is a considerable labor operation, so it’s critical to use only the highest quality parts, and fully service the system to prevent repeat failures.

This often first evidenced by a leak of oil under the car, which may be found during a service visit, and later will show up on the ground. The leak can range from a couple drops on the driveway to a pool. In extreme cases, the MIL (Check Engine Light) will illuminate due to a vacuum leak out the seal, as the engine will be running lean, more about that below.

Symptoms and Diagnostics
When the rear main engine seal fails, you will find an oil leak coming from the bottom of the vehicle where the engine and transmission meet.  Ensure the leak is not coming from higher up on the engine before deciding the main seal is bad, cam cover gaskets and front timing covers leaks must be handled first. Cleaning the oil from the engine, and the use of an oil based UV Dye Leak Tracer is a good method for confirm the diagnosis.

As the engine uses a sealed crankcase system, you also may experience fault codes like P0171 – System too lean, or misfire fault codes P0300, P0301, P0302, P0303, and/or P0304.  It is essential to note that these fault codes should only be considered as potentially related to a bad rear main seal if you are experiencing an oil leak from the area between the engine and transmission where the rear main seal is located and absent an oil leak are NOT a diagnostic indicator for rear main seal replacement.

Causes
Rear engine main seal failures will often be caused by two things, the first, a failed Crankcase Vent Valve and PCV system which causes excessive crankcase pressure (PCV) issues, and the second, the seal design itself.

Crankcase Vent Valve
VW Technical Service Bulletin 2015505/1 discusses increased oil consumption and blue smoke. Upon inspection, oil can be found in the air intake hoses after the turbocharger, and the oil can be seen leaking from the oil filler cap.

The cause of the problem is that the guide pin (see yellow arrow) that is part of the check valve in the intake manifold side of the valve may break, preventing the check valve from correctly sealing when boost pressure is present in the intake manifold. Intake boost pressure will be applied to the engine crankcase, resulting in oil leaks and the prevention of engine oil from properly draining from the turbocharger through the oil return line.

In addition, infrequent oil changes, extended service intervals, or oil changes with the incorrect oil and filter can lead to a build-up of sludge in the engine, and clog or damage the Crankcase Vent Valve and PCV system. Once clogged, the effect of this is too much pressure building up in the crankcase, and the PCV isn’t venting it out correctly. When this occurs, over time, it causes the rear main seal to blow out and begin leaking.

We have also heard possibilities of this issue becoming prevalent due to using incorrect spec oil, but a failed Crankcase Vent Valve and PCV system in fact causes most failures. The part has been redesigned, and there is a superseded part number; always double-check with Audi/VW/Porsche electronic service information to ensure the latest and greatest part is installed.

The Seal Design
The other cause we mentioned is the main seal design itself. The OEM rear main seal utilizes a poorly designed PTFE “sealing lip” in an inexpensive stamp steel housing, which over time and with overpressure, can separate and lead to an oil leak between your engine and transmission.

In the past,  the seal was almost always housed in a rigid aluminum rather than stamped steel housing. There is an upgrade for some cars, using a conventional old-school, durable rubber seal, which we highly recommend.

Correction
Because of this issue with the PCV becoming so prevalent, VW has issued redesigned seals that resolve the issue at hand, but do not automatically fix or prevent a pre-existing failed or failing rear main seal.

It is important to note that if you have an issue with your rear main seal leaking on your VW or Audi 2.0T TSI engine, you should definitely replace your Crankcase Vent Valve and PCV system at the same time. Failing to do so may result in premature replacement rear main seal failure. Whenever we replace a rear main seal, we always quote replacing the PCV with the updated version (if it hasn’t been already), the rear main seal, and normally a full synthetic oil change with VW spec oil.

Upgrade
For some cars, a billet aluminum rear main seal kit is designed to replace the failure-prone stamped steel factory part. This billet aluminum rear main seal kit is CNC machined from 6061-T6 Aluminum and features an OEM Viton Elring seal with an integral tension spring to ensure a tight seal to the crankshaft. The OEM rear main seal utilizes a poorly designed PTFE “sealing lip” which, over time, leads to an oil leak between your engine and transmission.

This kit has been tested and proven to last under high heat and is an excellent upgrade for replacing your leaking rear main seal. It is also an outstanding preventative maintenance modification that can save you from future headaches of oil leaks, stained driveways, and reduced performance that a leaky OEM rear main seal brings with it.

How We Can Help You
The Service Team here at Atlantic Motorcar is well experienced in this issue and others; with over 35 years of European auto specialization, serving clients from the areas of New England, we are familiar with the needs of the special service of your auto.

As Maine’s leading European auto specialists, we provide expert-quality services at a fair rate than nearby dealerships and specialty shops. If you’re experiencing any of the above-mentioned symptoms in your auto, please call us immediately; we can usually see your car the same day! At Atlantic Motorcar, we’ve developed some very specific procedures and tooling, combined with our expert technicians, to make this otherwise onerous repair a snap.

Finally
Questions or if we can help with service on your Audi, BMW, Mercedes, Sprinter, Honda, Infiniti, Lexus, Mini Cooper, Porsche, Volvo, and VW, don’t hesitate to get in touch with us. Our team of Service Specialists is here to help, for even the newest autos! (207) 882-9969.

Knowing, not just “doing,” that’s the Atlantic Motorcar Center way.
Thanks!

Warmly,
The Atlantic Motorcar Center Service Team

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Porsche 911, 912 and 914 – Steering Tie Rod Upgrade Kit – Conversion To Turbo Tie Rods

Case Studies

Background
First off, if you don’t know much about steering tie rods, the basic definition is that it connects the steering rack (in this case, a gear-driven box that translates turning the steering wheel into side-to-side motion to turn the front wheels known as a “rack and pinion”) to the wheel hub assembly (brakes, rotors, wheel, tire, etc.). It “ties” the track to the wheels.

The steering rack is up in the car’s underside, and the wheel hubs both turn and go up and down. So you need something that “ties” it together but can also handle all this movement. So it becomes a very fancy thing that needs two joints to be able to handle the movement. It could be a solid, straight bar if it didn’t have to move up and down and change the angle of motion. But it does. So we have two joints on it to do its job and manage the angles.

Original Porsche Design
On basically all Porsche 911, 912, and 914 models from 1969 through 1989, the tie rods look like the one shown below in the “Old vs New” photo. The exceptions may be cars already serviced and updated. The old tie rod has a normal ball joint at the wheel side (the “tie rod end”) like the new one. But at the other end, the old tie rod has an angled hinge-type joint with rubber bushings. On the outer end, which attaches to the wheel spindle, is the traditional tie-rod end with a ball and socket-type joint on the suspension upright end.

Why Update Needed
However, on the steering rack end, the inner tie rod is a strange-looking joint that houses a rubber bushing. Porsche designed this to help quell steering wheel vibration on their sports cars and installed this rubber bushing rather than the now traditional ball and socket type joint. Given the design and materials of the late 1960s, this rubber bushing was probably not too bad when it was brand new, but over time it wears down, and you lose a lot of steering feel and directness with this nasty old rubber. Again, every air-cooled Porsche used this tie rod style for two decades. That is, every air-cooled Porsche except one.

Then The Porche 930 Happened

It was in 1976, Porsche introduced the 911 Carrera Turbo (type 930) with a 3-liter engine and a turbocharger providing additional shove. It was a phenomenal car, a world-beating car even, an insanely fast car in its day. Because the Turbo was a bit of a handful to drive, Porsche wanted to make sure there was not any steering bind or even momentary delay in the response of the front wheels to the driver’s steering inputs. As a result, they removed the standard tie rod and replaced it with a metal-on-metal ball and socket-type joint at the steering rack.

Recommendation
Since then, Porsche enthusiasts have figured out that the two styles of tie rods are interchangeable and have installed several thousand sets of Turbo Tie Rods on non-turbo Porsches. Which is exactly what we do here. The kit shown below is the Porsche 930 kit, which we retrofit to the early 911s, 912, and 914 we care for.

Next Steps – Proper Alignment
After the tie rod update, a proper four-wheel tracking alignment must be carried out.
Our workshop uses the Mercedes Benz of alignment machines, the Hunter Hawkeye Elite, recommended by most of the major European auto manufacturers.
There are four key measures to each alignment: caster, camber, toe, and thrust angle, and we’ll explain those below.

Camber
This suspension angle shows how the tire angles away from 0 degrees vertical when viewed from either the front or rear of the vehicle. Expressed in degrees, negative camber means the top of the tire tilts toward the vehicle’s center, while positive camber means the top tilts away from the center. A visual cue for a camber problem is excessive tire wear on the inner or outermost ribs.

Caster
This angle shows the forward or backward slope of a line drawn through the upper and lower steering pivot points when viewed directly from the side of the vehicle. Also expressed in degrees, caster is measured by comparing a line running through the steering system’s upper and lower pivot points (usually the upper and lower ball joints of an A-arm or wishbone suspension design or the lower ball joint and the strut tower mount of a McPherson strut design) to a line drawn perpendicular to the ground. Caster is said to be positive if the line slopes toward the vehicle’s rear at the top, and negative if the line slopes toward the front. A visual cue for a caster problem is serious tire scrub laterally across the tread face.

Toe
Identifies the direction in which tires are pointed relative to the vehicle’s centerline when viewed from above. Toe can be expressed in either degrees or fractions of an inch. When looking down upon a vehicle, “toe-in” is when the leading edge of the tire is pointed toward the vehicle’s centerline. Conversely, “toe-out” refers to a tire face that points away from the vehicle centerline. The toe setting is typically used to help compensate for the suspension bushings’ compliance to enhance tire wear. Service Tip – The toe alignment also can be used to adjust vehicle handling; for vehicles that “wander,” the toe can be set slightly more toed in for directional stability. 

Thrust Angle
Consider an imaginary line drawn perpendicular to the rear axle’s centerline. This measure, expressed in degrees, compares the direction in which the rear axle is aimed at the vehicle’s centerline. The thrust angle also confirms if the rear axle is parallel to its front axle and that the wheelbase on both sides of the vehicle is the same. If the thrust angle is incorrect on a vehicle with a solid rear axle, it often requires a trip to the frame straightening shop to correctly reposition the rear axle.

Tech Note
There are various reasons for any of these alignment measures to be incorrect. At the same time, adjustment angles can be adjusted by a skilled technician to correct for inherent vehicle problems, correct for unusual tire wear, or to improve the performance and feel of a vehicle.

Alignment Specifications
All vehicle manufacturers have set specific alignment specifications for each vehicle. These are the “preferred” angles for camber, caster, and toe (with the preferred thrust angle always being 0 degrees). OEMs also provide the acceptable “minimum” and “maximum” angles for each specification and are usually within plus or minus one degree of the preferred angle.

Vehicles With Steering Angle Sensor
Sometimes, an additional labor operation must be performed to calibrate the steering angle sensor. The Steering Angle Sensor is what tells the onboard system if the steering wheel is pointing straight, left, or right and by how many degrees. Suppose the steering angle sensor data does not match with the rest of the vehicle data. In that case, the traction control system will likely trigger a plausibility error because the car doesn’t match what the steering angle sensor tells it. As mentioned, this is a separate labor operation from a standard four-wheel alignment and will be billed separately.

How We Can Help You
The Service Team here at Atlantic Motorcar is well experienced in this issue and others; with over 35 years of European auto specialization, serving clients from the areas of New England, we are familiar with the needs of the special service of your auto.

As Maine’s leading European auto specialists, we provide expert-quality services at a fair rate than nearby dealerships and specialty shops. If you’re experiencing any of the above-mentioned symptoms in your auto, please call us immediately; we can usually see your car the same day! At Atlantic Motorcar, we’ve developed some very specific procedures and tooling, combined with our expert technicians, to make this otherwise onerous repair a snap.

Finally
Questions or if we can help with service on your Audi, BMW, Mercedes, Sprinter, Honda, Infiniti, Lexus, Mini Cooper, Porsche, Volvo, and VW, please contact us. Our team of Service Specialists is here to help, for even the newest autos! (207) 882-9969.

Knowing, not just “doing,” that’s the Atlantic Motorcar Center way.
Thanks!

Warmly,
The Atlantic Motorcar Center Service Team

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Bosch CIS (Continuous Injection System) or K-Jetronic Demystified

Case Studies

Background
So you bought a vintage Audi, BMW, Mercedes, Saab, Volvo or VW with the Bosch CIS fuel injection system. To which I say, “Cool” I cut my teeth on CIS as a young tech back in the 80s and 90s, and have a strong fondness for the system. The design is typically German, simple, reliable, and very ingenious.

Bosch CIS Is K-Jetronic
Bosch CIS (Continuous Injection System) or K-Jetronic, has earned an unfair reputation as being difficult to service as it is largely a hydraulic system relying on pressures and pressure differentials to function.

No Scan Tools
One can’t just plug into it with a scan tool and find answers; it requires understanding how the system operates to know normal and abnormal parameters. On the other hand, since it is largely a mechanical system, there are far fewer things to go wrong with it, and it is nearly bulletproof.

Theory Of Operation
The Bosch K-Jetronic (K-Jet) system comprises different components, which are discussed below, and their functions. Only the components related to the system are shown below. The K-Jet system belongs to the group of CIS injection systems, which stands for “Continuous Injection System.” This means that the fuel is continuously injected into the inlet manifold. The system is completely mechanical, relying on pressures and pressure differentials to function.

From the end of 1979, this system was modified by adding a lambda control system (oxygen sensor to create a closed-loop mixture control system. This new system was known KA-Jetronic, or K-Jet with Lambda. This system is shown in the figure below; the components 11, 12, 16, and 18 are specific to this lambda control system and are, therefore, not present in a mechanical K-Jet system.

From Cold Start
Let’s take it from a cold start. Cranking the starter triggers the cold start valve to spray into the intake plenum on early models. Due to flooding problems, a thermo-time sensor was added to prevent the cold start valve from spraying fuel for more than 8 seconds and when the engine temp is warm.

The control plunger inside the fuel distributor moves according to how much air deflects the air sensor plate and is also affected by control pressure. Control pressure acts on the top of the control pin; cold control pressure is low, about 1 bar (15 psi), depending on the model, which lessens the resistance of the air sensor plate to rise. As the engine temp comes up, the control pressure rises, and the resistance increases leaning out the mixture (hot control pressure is about 3 to 3.5 bar (50 psi).

The internals of the fuel distributor determines how much fuel is output to the injectors. There are two chambers separated by a stainless steel diaphragm; the lower chamber is system pressure set by a small spring and is adjustable but almost never necessary. When the control plunger rises, this allows system pressure into the upper chamber; once the pressures in both chambers are equal, the spring pressure deflects the diaphragm and let’s fuel out to the injectors. Note the diagram below.

So let’s look at each component of a typically K-Jet system.

1 – Fuel Tank
Unfourtantly its greatest enemy is water, which wreaks havoc on the small metering passages in the fuel distributors and filter screens in injectors and ports.

2 – Fuel Pump
The fuel pump is used to supply the system with the necessary fuel pressure. A non-return valve is installed just after the fuel pump, which is needed to keep the system pressurized after the engine has been switched off; this allows for easy warm starts. The design is an electrical roller type with a check valve to prevent backflow and a relief valve in case of restriction.
system pressure = 80 psi or 5.5 bar (14.7 psi  = 1 bar)

3 – Fuel Acculator 
The fuel accumulator has two functions:
– After the engine is switched off, this accumulator keeps the fuel system under pressure to promote a warm start.
– The accumulator dampens out the fuel pulses generated by the fuel pump. A large spring-loaded diaphragm to keep fuel pressure up with the engine off also dampens pulses from the pump.

4 – Fuel Filter
The purpose of the fuel filter is to filter the fuel so that it does not pollute the system. Keep the filters clean; we now recommend replacement yearly and water out of the tank (which goes for extended sitting with alcohol fuel), and the system lasts nearly forever.

5 – Warm Up Regulator / Control Pressure Regulator
The purpose of the warm-up regulator is to help enrich the fuel mixture during a cold start. The mixture is adjusted to the correct ratio when the engine warms up. This component can be overhauled, and we have had great success in cleaning and servicing these units, many of which are no longer available. An electrically heated bi-metallic strip operates a valve controlling fuel pressure to the distributor. Some units have a vacuum diaphragm that provides enrichment during acceleration.

6 – Fuel Injector
The injector provides a nicely atomized fuel to make the fuel-air mixture as homogeneous as possible. Not an electrical design; think of it as a mechanical valve that “pops” when the fuel pressure reaches approximately 45 psi (3 bar). All injectors in A K-Jet system spray at the same time the same amount; there is no timing as with a mechanical injection system. These are usually quite reliable, as long as water or debris doesn’t enter the fuel system. They do have rubber o-ring seals that need replacement from time to time.

7 – Cold Start Fuel
Discharged from the Cold Start Injector is present only when the engine is cranking over, as the operating voltage is derived from the starter solenoid.

8 – Cold Start Injector
Working in connection with the Thermo-time switch, the cold start injector adds extra fuel at very low ambient temperatures to assist when starting the engine. These only operate when the engine is cranking over, as the operating voltage is derived from the starter solenoid.

9- Fuel Distributor
The fuel distributor is the mechanical heart of the system, supplying the different cylinders with exactly the same amount of fuel. Some versions have an internal fuel pressure regulator to keep the system pressure constant. The main moving part is a central plunger which is controlled by the air sensor plate. When the throttle is opened, the increase of air into the manifold causes the air sensor plate rises and pushes the control plunger which allows fuel out to the injectors. Mixture adjustment is via the 3 mm Allen screw. This part can be serviced or rebuilt only with great care and proper tools. This is very easily damaged by debris or water in the fuel.

10 – (Mechanical) Air Flow Meter
The mechanical air flow meter measures the amount of air drawn in by the engine by employing a “teeter-toter” pivoting lever to access the metering plunger in the fuel distributor. Based on this measurement, the fuel mixture is mechanically adjusted. These are quite robust and rarely require service or adjustment.

11 – Frequency Valve / Timing Valve
This control valve is used with KA-Jetronic systems. Here the fuel mixture is regulated by means of a lambda-probe control system. The control valve changes the pressure between the upper and lower chamber of the fuel distributor, thus changing the fuel mixture.

12 – Lambda (Oxygen) Sensor
The lambda-sensor (only on KA-Jetronic) generates a signal that the control unit uses to adjust the fuel mixture. A special ceramic material that senses the difference between the O2 in the exhaust (or lack thereof) and the ambient O2 and produces a voltage that is sent to the Lambda Control Unit to adjust the CO in a closed loop system. The voltage fluctuates between a few millivolts and just less than 1 volt. The early single-wire (unheated) lambda sensor only generates a signal if the component has a sufficiently high temperature.

13 – Thermo-Time Switch
The thermo time switch controls the injection time of the cold start injector (8).  If a lambda control system is fitted, this sensor is also used as an input for the control device (computer) (18).

14 – Igntion Distribotor
It is not directly connected to the CIS system, noted only for diagram continuity.

15 – Auxiliary Air Valve
The purpose of the auxiliary air valve is to supply more air when the engine is cold. This air slide can be operated electrically or can be directly connected to the coolant system to change the system state.

16 – Throttle Position Switch / Position Sensor
The throttle switch is only used in systems with a lambda control system. This switch is present so that the control unit knows the throttle position for idle speed control.

17 – Engine Control Unit / Computer 
The control unit (ECU) processes the various inputs to provide the desired signal to the control valve (11), thus optimizing the fuel mixture. This unit is only present with KA-Jetronic systems or K-Jet with Lambda.

How We Can Help You
The Service Team here at Atlantic Motorcar is well experienced in this issue and others; with over 35 years of European auto specialization, serving clients from the areas of New England, we are familiar with the needs of the special service of your auto.

As Maine’s leading European auto specialists, we provide expert-quality services at a fair rate than nearby dealerships and specialty shops. If you’re experiencing any of the above-mentioned symptoms in your auto, please call us immediately; we can usually see your car the same day! At Atlantic Motorcar, we’ve developed some very specific procedures and tooling, combined with our expert technicians, to make this otherwise onerous repair a snap.

Finally
Questions or if we can help with service on your Audi, BMW, Mercedes, Sprinter, Honda, Infiniti, Lexus, Mini Cooper, Porsche, Volvo, and VW, please contact us. Our team of Service Specialists is here to help, for even the newest autos! (207) 882-9969.

Knowing, not just “doing,” that’s the Atlantic Motorcar Center way.
Thanks!

Warmly,
The Atlantic Motorcar Center Service Team

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Porsche 911 – Smoking On Start Up – Q & A And The Why

Case Studies

Background – Recently, we had a client ask us about slight oil smoke at the start up of his Porsche 911. If one person asks, it usually means that at least ten other folks have the same question. So, we thought sharing this here might be a solid idea.

Question – “Hi Bruce. Thank you for the follow-up note. Much appreciate your work on my Porsche 911. Question – when I start it up cold, It does blow some smoke. How concerned should I be? Or not. It’s got 45k mileage and is now ten years old.

Answer – Very common with 911 to have some slight smoke on start up. It’s the nature of the Porsche flat 6 engine that oil can seep into or past the rings when the engine has been sitting some time. It should clear up in a few minutes of running.

Technical Reason
The technical answer is that the smoke on start-up is caused by the engine “wet sumping”. That is, some the oil in the oil tank drains down into the crankcase overnight. The 911 engines are a dry sump oiling system. This means, that the crankcase is purged of oil when the engine is running.

Also if your oil tank level is slightly too high the sump can fill and oil can enter the cylinder, via the rings and cause the smoking at startup. Even a different parking angle can cause this condition. Once the engine is stopped and over time, the oil works down into the crankcase and floods the bottom end. That oil level is now backed up against the pistons and crankshaft.

Once re-started some oil has saturated the piston ring packs and the crank webs, and you get smoke till it burns off. It is not a problem once running as the oil pump has a pressure side and a scavenge side. The scavenge side has much more pumping capacity than the pressure side and quickly empties the crankcase of oil. The trick to keeping a 911 from smoking at start-up is to drive the car every day and be sure there are no air leaks in the breather (that long hose from the back of the engine to the top of the oil tank).

Link
A link to an excellent article with more detail can be found at – https://tinyurl.com/911engineoildesign.

Avoiding This
Factors that make it less likely include a good service history and a usage that isn’t inner city or predominantly short journeys (where the engine is always running with a rich mixture and excess fuel can dilute the oil). The 20K/2yr service intervals also haven’t helped with engine life when diluted oil isn’t often changed in such an urban environment.

Preventative Maintenance
We would strongly advise changing your car’s engine oil every six months or 5,000 miles, preferably with oils formulated with increased levels of Moly additives that most oils do not have, which in turn helps to protect the cylinder walls. Doing so will help the oil remain free of contaminants that could lead to Porsche cylinder bore scoring. Models that have been well maintained with good service history and a healthy cooling system will reduce the chance of localized overheating. More frequent oil changes may be necessary if you track your car, drive short distances, or operate the engine in cold climates.

How We Can Help You
The Service Team here at Atlantic Motorcar is well experienced in this issue and others; with over 35 years of European auto specialization, serving clients from the areas of New England, we are familiar with the needs of the special service of your auto.

As Maine’s leading European auto specialists, we provide expert-quality services at a fair rate than nearby dealerships and specialty shops. If you’re experiencing any of the above-mentioned symptoms in your auto, please call us immediately; we can usually see your car the same day! At Atlantic Motorcar, we’ve developed some very specific procedures and tooling, combined with our expert technicians, to make this otherwise onerous repair a snap.

Finally
Questions or if we can help with service on your Audi, BMW, Mercedes, Sprinter, Honda, Infiniti, Lexus, Mini Cooper, Porsche, Volvo, and VW, please contact us. Our team of Service Specialists is here to help, for even the newest autos! (207) 882-9969.

Knowing, not just “doing,” that’s the Atlantic Motorcar Center way.
Thanks!

Warmly,
The Atlantic Motorcar Center Service Team

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Porsche Cylinder Bore Scoring – Our Thoughts On This – The Simple Truth

Case Studies
True Bore Scoring – Photo LN Engineering

Porsche M96/M97 Bore Scoring
There are many articles online and various posts in Porsche forums about bore scoring issues and engine failure; if one were to believe what they see online, they’d think it was an endemic problem. The simple truth is that while cylinder bore scoring has been an issue on a relatively small percentage of 996 and 997 models, it isn’t a universal problem.

If you look at the photo gallery below, you will see typical wear and light scoring found in almost every car on the road. This is not a reason to panic, but rather a reminder to take extra care and precautions with your Porsche. Below, we’ll share our feelings on this issue and what you can do to mitigate it or, ideally, prevent it from occurring in the first place.

How Does It Happen?

The M96/97 Crankcases use ‘Lokasil’ Cylinder liners (a flexible but hard-surface metal matrix composite). Due to the layout of the open deck crankcase on 996/997 models, the cylinder banks are not rigidly supported like the first generation 928, 944, and 968 water-cooled engines. Another factor in the M96/97’s engine design is the difference in lubrication and cooling.

The oil spray and coolant face the lower side of the cylinders, which means the piston thrust on the right-side cylinder runs slightly hotter than the left-side. When thermal and mechanical stresses are applied across the two banks of cylinders, the sixth cylinder becomes hotter. This, in turn, causes the sixth cylinder to become slightly oval in shape, causing more friction between the cylinder and the wall, which results in the cylinder lining being rubbed away.

Once the protective cylinder lining is damaged, the cylinder is in direct contact with the wall, which causes scarring. In addition, a two-year oil change interval (DON’T DO THAT!) compromises cylinder lubrication. When fuel and moisture contaminate the oil (due to low mileage short journeys), the oil becomes diluted, which results in friction between the piston and the cylinder bore wall and localized overheating.

Borescope Results For Porsche 911 (Click to enlarge)
Other than cylinders 5 and 6, we’d consider this normal wear on this engine. Cylinders 5 and 6 show some marking, but nothing compared to what would be thought of as severe bore scoring, as noted in the LN Engineering image above. A stuck piece of carbon, other impurities, or a high engine rev on a cold engine might have caused the slight galling present on cylinder 5, whereas cylinder 6 looks like some debris was caught in a piston ring. Dirty engine oil, extended change intervals, or low-quality oil may have also contributed to it.


Additional Reading

A full, in-depth article on this issue and other export opinions can be found here by our friends at LN Engineering –
https://lnengineering.com/products/watercooled-porsche-cylinders-sleeves-and-pistons/bore-scoring/tips-on-how-to-prevent-porsche-bore-scoring.html

Porsche Models Prone To Bore Scoring
All water-cooled 911 Boxsters and Caymans from 2004 through 2009 are at risk of suffering from bore score; however, it appears the percentage of engines actually affected is quite low.

“Porsche GB advised that it sold 9710 E 996s and 997s in the model years 2004-2006. Some very wet-finger-in­the-air guesswork suggests independent specialist rebuilds and OPC warranty replacements combined may have reached 500 engines from that period, which indicates an overall percentage of around five percent.” (Source: GT Porsche Magazine)

Symptoms of Bore Scoring
• A rhythmic noise that sounds similar to that of an exhaust leak
• One exhaust pipe has more soot than the other
• Increased oil consumption
• Extremely black engine oil
• Pooling of oil within the cylinders
• Aluminum debris was found in the oil filter and engine oil sump.

Realize It’s Not The End Of The World
Consider that for an engine that has traveled 60,000 miles; each piston has gone up and down over 300 million times on average, leading to serious damage and, potentially, eventual engine failure if the required preventative maintenance has not been carried out. Slight to moderate bore scoring is not the end of the world or the end of your engine. It may increase oil consumption or provide an occasional puff of smoke at start-up, but in no way does slight to moderate scoring indicate the need for engine teardown. Engines like this might last 30K, 40K, 50K, or even 100K miles before the effects are severe enough to warrant attention. It is something to be aware of, to try and mitigate, but we don’t believe that it deserves the amount of attention that is often focused on it on the internet. Run your car, enjoy it, and don’t worry.

Avoiding This
Factors that make it less likely include a good service history, a healthy cooling system (to reduce the chance of localized cylinder overheating during the warm-up or over-run), and a usage that isn’t inner city or predominantly short journeys (where the engine is always running with a rich mixture and excess fuel can dilute the oil). The 20K/2yr service intervals also haven’t helped with engine life when diluted oil isn’t often changed in such an urban environment.

Preventative Maintenance
We would strongly advise changing your car’s engine oil every six months or 5,000 miles, preferably with oils formulated with increased levels of Moly additives that most oils do not have, which in turn helps to protect the cylinder walls. Doing so will help the oil remain free of contaminants that could lead to Porsche cylinder bore scoring. Models that have been well maintained with good service history and a healthy cooling system will reduce the chance of localized overheating. More frequent oil changes may be necessary if you track your car, drive short distances, or operate the engine in cold climates.

How We Can Help You
The Service Team here at Atlantic Motorcar is well experienced in this issue and others. With over 40 years of European auto specialization, serving clients from the New England areas, we are familiar with the needs of your auto’s special service.

As Maine’s leading European auto specialists, we provide expert-quality services at a fair rate compared to nearby dealerships and specialty shops. If you’re experiencing any of the above-mentioned symptoms in your auto, please call us immediately; we can usually see your car the same day! At Atlantic Motorcar, we’ve developed some very specific procedures and tooling, combined with our expert technicians, to make this otherwise onerous repair a snap.

Finally
If you have questions or if we can help with service on your Audi, BMW, Mercedes, Sprinter, Honda, Infiniti, Lexus, Mini Cooper, Porsche, Volvo, or VW, please contact us. Our team of Service Specialists is here to help with even the newest autos! (207) 882-9969.

Knowing, not just “doing,” that’s the Atlantic Motorcar Center way.
Thanks!

Warmly,
The Atlantic Motorcar Center Service Team

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Porsche 911 (Type 991) – Engine Cover Latch Release Problem, and Correction

Case Studies

The Vehicle
The Porsche 911, type 991, is prone to a common problem relating to the remote release of the engine deck lid from the passenger compartment. We recently saw this at Atlantic Motorcar Center with a new client car and thought it would make an excellent case study.

How This Happens
It is not uncommon when service is being carried out on the car for the actuator, the electromechanical device that pulls on the cable, to become disconnected from the rear deck lid latch or to be moved out of the bracket on the actuator itself. This prevents the rear engine deck lid from opening. The actuator and cable are located on the passenger side of the engine bay, very close to the engine oil filter, and with the tight space, it is easy to knock the cable loose. This might not even be discovered until the next time service is done and the rear engine compartment can not be opened. Porsche has an emergency release cable in place in the event of an actuator failure, but this is only useful in the event that that cable is still attached to the latch.

Generally, there are three failures if you have a problem with the rear engine lid not opening. This tech tip will give you information on how to diagnose the nature of each failure and then how to gain access and correct it without damaging the car.

Problem
The first failure would be a failure of the latch actuator itself. The lock actuator is like an electric motor that pulls on the cable attached to the latch. Should the lock actuator fail, this is easily overcome by the emergency release located under the rear spoiler. That releases a cable that is attached to the end of the lock, actuator latch, and actuator, which allows you to remotely unlock the rear engine cover in the event of an actuator failure.

Trust But Verify
If you have access to an engine borescope, you can likely sneak that under the rear spoiler when it’s raised and over or under the plastic engine fan housing to get a view of the latch. You’ll note on the picture here that we could verify that the latch cable had popped out before disassembly. This can save considerable time and effort to understand if it is simply an electrical fault that can be reversed easily or a cable or latch issue, necessitating a more complex solution.

Failure Mode One – Actuator Or Controls
It’s easy to diagnose a failure of the actuator if, when operating the rear deck lid switch in the passenger compartment, you don’t hear the actuator motor run, which sounds like a whirling noise that lasts for about 2-3 seconds, then chances, are you have a failure of the actuator, the switch or the wiring and voltage supply. You still should be able to access the emergency cable and open the deck lid so you can diagnose and correct the problem.

Failure Mode Two – Cable To Bracket
The next cause is a failure of the cable which retains which connects the actuator to the latch itself. The cable itself is quite robust and unlikely to break on its own accord. However, because of its proximity to the engine oil filter, which is commonly accessed during service, it’s easy to knock the latch actuator cable out of the metal bracket on the actuator side. If this occurs, even the emergency cable will not allow access to the engine compartment, as the latch actuator cable is no longer properly connected, and the sheath will move back and forth. We’ll talk about how to overcome this failure mode shortly.

Failure Mode Three – Cable To Latch
The final cause of failure, and perhaps the most common, is when the latch actuator cable becomes disconnected from the latch itself. In this case, the plastic retaining clip that holds the cable onto the latch becomes displaced, which often occurs during service or changing the engine oil filter due to its proximity. If this occurs, even the emergency cable will not allow access to the engine compartment, as the latch actuator cable is no longer properly connected.

Why This Happens
Porsche has made no provision for positively anchoring the cable line into the latch; rather, it is not retained by a screw or bracket and only requires a small bump to become disconnected and misplaced from the latch. When this occurs, and it is not noticed before the engine cover is closed. Access to the engine cover is impossible, either through the emergency cable or the latch actuator. The cable will still move, but because it is no longer attached to the latch release arm, it does not operate the latch.

Photo Gallery – Visual Of Our Process

Correction – First, Do No Harm
The important thing is to protect the car from any damage; the correction, though it takes time, it’s not exceptionally difficult, especially with an automotive lift and the assistance of a teammate. We suggest using blue painter’s tape on any sharp edges, corners, or exposed areas of the paint to protect the finish.

Step One
The next step is to remove the rear, bumper, and carrier from the vehicle; this does take some time and will require the assistance of a teammate to ensure the damage does not occur, either to the car or to the bumper cover. Once the bumper cover is removed, it can be placed on top of large trash, container, or workbench to protect the finish from damage.

Step Two
With a bumper cover removed, you’ll need to remove the air intake boot from the engine and throttle body to access the area directly under the engine cover latch. If you’re very lucky, you may be able to snap the cable back into the latch and then use the remote control inside the car to operate the cover.

Step Three
If you find that difficult, the next best solution is to simply fabricate out of a stiff wire at a 90° angle pic, with a gentle bend to get around the engine. Using a mirror and a flashlight, place the end of that pic inside the area of the rear deck lid latch, where the cable normally goes, and operate the latch to the passenger side of the car until the rear deck lid opens. It will take firm and steady pressure rather than a fast pull.

It may take several tries with this method before you have success. Take your time, and ensure that no damage occurs to you or the car. If the latch still does not release, it is possible that you have a mechanical problem with the latch itself. You can still access the latch retaining bolts, two 10 mm bolts, from underneath, and once unbolted, raise the deckled to remove the failed latch.

Step Four
Once you have the rear engine cover open, you’ll need to remove the plastic cover that retains the two cooling fans on top of the engine. Be careful of the two wires that are used to power the fans; the connectors are small and can be fragile from the heat of the engine bay. Once you have that fan cover removed, you should be able to look in the center back portion of the engine bay and locate the release latch in the center back of the opening.

Step Five
We suggest removing the latch from the body of the vehicle. You’ll find it retained by two 10 mm bolts about an inch or so long. Removing those is easy, and you’ll probably find factory marks already described on the latch to show you its installed location; if not sharpie or grease pencil can be used to create your own witness marks so that the latch may be reinstalled in the correct position.

Step Six
Once you have removed the latch, you can install the cable carefully, snapping the retaining clip on the passenger side of the latch in place. You’ll note that that is not a very secure connection, and although it may work, it would be easy to displace again. May be a good idea to clean and lubricate the latch with some silicone spray.

Before testing the latch in the actuator, make sure the cable end closest to the actuator is actually snapped into the black metal bracket. If this is not snapped into the bracket, the cable will not operate correctly, as the sheath will move back and forth.

Final Step
With a cable verified to be correctly installed on both ends, we suggest operating the actuator a few times to verify the latch is working correctly before remounting it onto the body. Once the latch is installed back onto the car and lined up with your witness marks, close the rear engine lid and verify latch operation and release. Do it several times just to be sure that it is reliable.

The Fix
While the actuator cable is retained with the plastic positive clip, we’re a big fan of the belt and suspenders approach and suggest fabricating a small metal bracket that can be placed under the passenger side latch retaining bolt removed earlier.

If you look at our picture, you can see that the short bracket, less than 2 inches long, covers and positively retains the actuator cable into the latch body. The cable can only be removed in the future by loosening one of the 10 mm bolts and rotating the bracket out of the way.

Check Both Ends
While this is an elegant solution to the problem on the latch end, one must still be cognizant of the potential ease of knocking the actuator and the cable out of the bracket there. Consider a carefully placed back nylon wire tie, or perhaps, just a check process to make certain on service that the lock actuator works before closing the engine cover. And then retest after the service is complete.

Reassemble In Reverse Order
At this point, with the latch reinstalled, the small bracket fabricated, and the operation of the latch thoroughly tested, simply reverse the process, reinstalling the air, boot air boxes, and rear engine cover, carefully lining everything up. Remove the blue painter’s tape placed for protection, and you should be ready.

Watch The Video
You can review a narrated short video of this tech tip on the Atlantic Motorcar YouTube page; see below.

How We Can Help You
The Service Team here at Atlantic Motorcar is well experienced in this issue, and others, with over 35 years of European auto specialization, serving clients from the areas of New England, we are familiar with the needs of the special service of your auto.

As Maine’s leading European auto specialists, we provide expert-quality services at a fair rate than nearby dealerships and specialty shops. If you’re experiencing any of the above-mentioned symptoms in your auto, please call us immediately; we can usually see your car the same day! At Atlantic Motorcar, we’ve developed some very specific procedures and tooling, combined with our expert technicians, to make this otherwise onerous repair a snap.

Finally
Questions, or if we can help with service on your Audi, BMW, Mercedes, Sprinter, Honda, Infiniti, Lexus, Mini Cooper, Porsche, Volvo, and VW, please contact us. Our team of Service Specialists is here to help, for even the newest autos! (207) 882-9969.

Knowing, not just “doing,” that’s the Atlantic Motorcar Center way.
Thanks!

Warmly,
The Atlantic Motorcar Center Service Team

 

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Porsche 944 and 951 – Balance Shaft Alignment During Timing Belt Service

Case Studies

AMC Tech Tip – Porsche 924/944/951 Balance Shaft Alignment
We have a very nice 951 in the workshop today that came in with a very noticeable vibration. Engine mounts had been recently replaced at another shop, apparently in an attempt to correct this.

Tis The Season

Spring is the season for Porsche 924/944 timing belt calls and quotes, and invariably someone always needs one “redone” because all the parts were not replaced or replaced correctly.

Important – No Shortcuts

There is a huge temptation to do the “economy job” on these, but this is a false economy, and over the years, I’ve seen timing belts replaced with the old balance shaft belt and tensioners left. They rarely make it to the next service, which results in significant engine damage when they fail. Do it right the first time, and you won’t have to pay twice. 😉

Easy oversight on this job is to mistime the balance shafts, so the weights on the shafts, which are meant to cancel out the engine vibration, actually ADD to it. Not a good thing.

Service Tips
There is real science and trick to doing this correctly, and over the last 30 years, we’ve corrected many of these that have come out of other service facilities. I’ve even made a mistake a few times but caught it quickly.

The trick in these cars is to be sure that not just the timing belt is replaced; you’ll want to ensure the water pump (driven by the timing belt), rollers, and tensioners get attention. Also, a quick look at the camshaft, crank, and balance shaft seals will save you headaches in the long run.

Questions, we’re here for you and your car!

Your Advocate, On Your Side
At AMC, because we are independent and locally owned, we are YOUR advocate. Knowledge, Integrity, Value.

Questions
If you have any questions, or need a copy of your service history, please do not hesitate to contact us directly. (207) 882-9969.

Thank you,
Bruce and the AMC Team

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