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.

Audi A3 2.0 TFSI Engine – Carbon Deposits

August 24, 2011

Case Studies

Atlantic Motorcar Center

Own a Audi model with the 2.0 TFSI engine? – Read on, we may be able to save you and your car from some real headaches. These engine seem to have developed a chronic problem with carbon deposits on the intake valves, which can lead to a very expensive repair. This carbon build up on the valves is caused by the direct injection, a common issue with engines of this type. It happens because the fuel is not being injected over the valves, this would keep the valves nice and clean. A secondary issue may also be the crankcase ventilation system, and the use of low quality engine oils.

They say prevention is better than cure so what can be done to prevent this carbon build up issue. Using good quality clean burn fuel free of bio elements, the higher octane fuels also tend to burn cleaner. Get the engine up to temperature as soon as you can (don’t idle it but just drive it steadily at around 2000rpm till it warms up) and keep the engine operating at 3000rpm for 15 minutes per week. At this RPM range the engine is designed to run hotter and this can help burn off some of the carbon deposits. Be sure to always use a OEM quality full synthetic engine oil, and change the oil often, no more than every 5,000 to 7,500 miles.

Driving the engine at just over 3000 RPM raises the temperature and puts the engine into a “cleaning mode” where it runs leaner and hotter clearing out a lot of the carbon build up inside the engine, so try to hit this sweet spot as often as you can and for at least 15 minutes per week. An ounce of prevention, always worth a pound of cure!

Volvo XC90 – AWD/AOC Drive Coupler Problem

August 23, 2011

Case Studies

Atlantic Motorcar Center

Tech Brief – Buying or own a used Volvo with 70K-120K miles? Make sure the All Wheel Drive System (AWD) is working, in fact, this may be something that you want your servicing shop or dealer to check the next time your Volvo is in for service. Over the past few months we’ve seen a total of 3 of these cars, all in the 70K-120K mile range, with inactive AWD. We check the AWD system each service, but if you are taking your Volvo to a general repair facility, then you may want to show them this article, unless you know what to look for it can be easy to miss.

Amazingly this problem does not turn on any warning lights or set a computer fault code, the only way you can tell, other than by an through inspection in the workshop, is by a loss of traction, the front wheels have drive power, the rears do not. In one case the problem was noted during a vehicle maintenance, on the other two – only when the owners brought the car in with a concern about a lack of traction.

Fortunately the repair is quite straightforward, if caught early. It consists of installing a revised or reinforced coupler from Volvo, yes, they seem to have updated the part design. Given the overall dependability of the Volvo AWD/AOC system, and the mileage at which these failures occurred, this is not a terrible fault. We think of the coupler as a form of a “mechanical fuse”, protecting the more expensive driveline components from failure.

VW Touareg – Four Wheel Brake Service

August 22, 2011

Case Studies

Atlantic Motorcar Center

Audi Q7/Porsche Cayenne/VW Touareg Brake System – The Touareg, and its closely related cousins, the Q7 and Cayenne are massive cars weighing in at well over 2 tons, and need an equally massive brake system.

We’re always impressed with these engineering marvels, here is a photo essay of the complete brake system and layout for a Touareg we are servicing in the workshop.

The front brake rotors are directional, with the cooling fins arranged for each side of the car, the brake calipers have six pistons for additional stopping power, and you’ll note a brake pad wear sensor on every brake pad, and the new hardware kit on each caliper – key to preventing brake noise and rattle. Brake life on this series is about 35-40K miles, and the front and rear brakes wear at about the same rate.

We used the new ATE coated brake rotors to cut down on the rust and corrosion which you would normally find on in very short order on brake rotors exposed to road salt.

VW Touareg – Four Wheel Brake Service

August 22, 2011

Case Studies

Atlantic Motorcar Center

We’re always impressed with these engineering marvels, here is a photo essay of the complete brake system and layout for a Touareg we are servicing in the workshop.

We used the new ATE coated brake rotors to cut down on the rust and corrosion which you would normally find on in very short order on brake rotors exposed to road salt.

Mini Cooper Clutch – When Good Clutches Go Bad

August 21, 2011

Case Studies

Atlantic Motorcar Center

Mini Coopers are wonderful cars, but Mini has a problem with clutches, no two ways about it. The early cars are subject to numerous Technical Service Bulletins on clutch problems and noises. What we’ve also seen is problems with excessive clutch pedal effort. The problem comes on rather slowly, is often not noticed by the driver, who becomes acclimated to it as he/she is using the clutch every day. Comparing your clutch pedal effort to another Mini is a good test, or stop by and ask us for a courtesy check. The key thing here to catch this BEFORE it damages the engine flywheel, an ounce of prevention is worth a pound of cure.

This nice Mini came in with the concern of a burning smell, and slipping clutch. The first thing we noted during the road test, aside from the burning smell, was the high level of clutch effort, it was really hard to depress the clutch. We found the cause, which we’ve seen more than once, the clutch release bearing hung up on the guide tube, keeping the clutch partially depressed and allowing slippage. After extended slippage, the heat build can be great enough to damage the engine flywheel. Since the Mini uses a “dual mass” or two part fluid filled flywheel, this can be a very expensive repair

Correction entailed a very light resurfacing of the flywheel, replacement of the complete clutch assembly, as well as the hydraulic actuating cylinder. With failures of this nature, it is important to always service as a system and replace all related components. For example, a sticking actuating cylinder, which disengages the clutch, can cause a repeat of the failure. Our customer could not believe the difference, a most pleasant surprise.

Audi/VW V6 Engines – Excess Crankcase Pressure Caused Oil Leaks

August 20, 2011

Case Studies

Atlantic Motorcar Center

We’ve noticed in our service facility that the Audi/VW V6 30 valve 2.8 liter engines can develop oil leaks as the car gets older and advanced in miles. The 2.7 engines with the twin turbo can develop a similar condition. We would like to bring to your attention a common issue with the crankcase breather hose system.

Many of these cars have a rough service history. We consider ‘rough’ to be irregular oil changes, use of non-synthetic engine oils, extreme hot or cold climates, a lot of short driving distances where full engine temperature is never reached, and excessive low RPM city driving. This use causes a great deal of condensation and moisture to form within the engine, producing a build up of sludge. Many owners have bought their car without knowing the oil change or driving history.

If you own or have just bought an Audi/VW V6 2.8 liter V6 30 valve with over a 100,000 miles that has oil leaks, the crankcase breather system should be treated as suspect. If you remove the valve cover and see a lot of resinous accumulation in the valve train area, this indicates that the vehicle already has heavy amounts of oil sludge build up throughout the engine. Suspect number one is the engine’s crankcase breather system.

Years of rough service history as mentioned above, cause contamination to take place inside the Audi/VW V6 engine which clogs the crankcase breather hose system. Due to this blockage, the air flow generated within the engine crankcase is restricted and will not allow the system to breath properly. When the engine is running, pressure builds up in the crankcase and causes oil to push out and leak from the weakest parts of the engine.

Due to these common issues with high mileage Audi/VW V6 2.8 liter V6 30 valve engines, we stock a complete rebuild kit to bring your vehicle’s crankcase breather system back into peak working order. After repairing the crankcase breather system it is common for engine oil leaks to subside and/or stop. If the leaks do not stop, we check these common oil leak points:
1) The cam chain tensioner gaskets and seals.
2) The camshaft cover gaskets.
3) The camshaft seals and plugs.
4) The front and rear crankshaft seals

Chances are one or more of these items, even if recently replaced, has been damaged by the excessive crankcase pressure in the engine. If your vehicle is experiencing oil leaks or related conditions, we recommend bringing this information to our attention for proper diagnosis, before engine damage occurs. Our goal is always to PREVENT, rather than correct problems, saving you both time and money.


Location Of Hose	Cracked Problem – Cracked Hose

2008 BMW 335XI – Electric Water Pump Replacement

August 19, 2011

Case Studies

Atlantic Motorcar Center

Most cars, including older BMWs, use a water pump which is driven by a belt on the front of the engine, a tried and proven design, but not one which allows dynamic control. As it has transitioned from the older “M” engine to the new “N” designs, BMW has come up with an interesting twist, an electric engine coolant/water pump.

An electric water pump is really a brilliant idea, it offers a higher level of control of the engine operating parameters. The electric pump can be turned on and off as needed to speed up engine warm up time and precisely control engine temperature. As an additional benefit the parasitic drag of a belt driven water pump is eliminated, in theory improving engine performance and fuel economy. Anything mechanical can fail, and the electric pump on this vehicle experienced just that, a failure of the electric motor to rotate the pump impeller and circulate the engine coolant.

Since this is a very new design, and few have seen the internal construction of the pump, we thought a photo documentary might be in order here. You’ll note the pump impeller is labeled “VDO”, a long time supplier to most of the German manufacturers. You may also note what appears to be a NiCad battery inside the pump electronics. This really caught our eyes here, and we’re in the processing of determining exactly what the purpose is. The capacity would seem to be too low to run the pump, but we’re see the engineers at BMW have a reason.

Volvo XC70 – Engine Oil Sludge – Low Oil Pressure

August 18, 2011

Case Studies

Atlantic Motorcar Center

This is a problem we see much more on Saabs than Volvos, in fact in the last 7 years I’ve seen this but 3 times. The photos tell it all on this one, symptoms where engine oil light on at idle and engine oil pressure very low. Sludge deposits were found in both the engine oil pump and pickup screen. The o-ring seals in the pan, a common cause of low pressure on these cars, were intact, looking to have been recently replaced.

A previous servicing shop had removed the engine oil pan and cleaned the pickup in an attempt to correct the problem, but they never removed the oil pump for inspection. We found the engine oil pump was clogged nearly solid with sludge, tremendously restricting flow and hence pressure. Only one cause for this on a car with this mileage, either a poor quality oil and/or filter, or infrequent engine oil services. A good quality engine oil, Castrol GTX or Syntech, a factory oil filter, and regular oil changes every 5,000 – 7,000 and chances are you’ll never hear the dreaded words “Oil Sludge”.

Clogged Engine Oil Pump – Note Sludge

August 17, 2011

Case Studies

Atlantic Motorcar Center

A Properly Cleaned Engine Oil Pan

VW Passat Heater Core Replacement – Clogged Core – Low Heat

August 16, 2011

Case Studies

Atlantic Motorcar Center

A heater core is a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle’s engine is passed through a winding tube of the core. Fins attached to the core tubes serve to increase surface for heat transfer to air that is forced past them, by a fan, thereby heating the passenger compartment.

The heater core is made up of small piping that has numerous bends.Clogging of the piping may occur if the coolant system is not flushed or if the coolant is not changed regularly. If clogging occurs the heater core will not work properly. If coolant flow is restricted, heating capacity will be reduced or even lost altogether if the heater core becomes blocked. You can see from the the photos this core was fully 3/4 blocked, doesn’t make for good heat on cold Maine mornings.

Because the heater core is located under the dashboard inside of the vehicle and is enclosed in the ventilation system’s ducting, servicing it requires disassembling a large part of the dashboard, which is rather time-consuming.