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.

Volvo S70 – Defective O-Ring Seals on Oil Pump Pick Up

July 27, 2011

Case Studies

Atlantic Motorcar Center

Car presented with engine making a moderately loud tapping noise, and via OBD-II a fault code was found to be stored for the variable engine valve timing solenoid. Upon inspection the technician noted that engine oil pressure warning light wire was disconnected. We connected wire and engine oil pressure warning light came on. A check of engine oil pressure with mechanical gauge showed pressure to be very low at idle, about 5 PSI, gauge is unsteady and flutters. During extended idle the reading will nearly drop to nearly zero at times. The low and unsteady gauge reading indicates possible cavitations in oil pressure.

Volvo has a somewhat common problem of defective oil pump pick up seals. These small rubber sealing rings serve to connect the engine oil pickup, located in the oil pan, to the engine block where the actual oil pump is located. After several years and thousands miles of engine heat, these seals become hardened and allow air to enter into the oil pickup system, preventing the oil pump from drawing the proper amount of oil. Early symptoms are a oil pressure light on at idle, or an engine that sounds unusually loud, often a tapping noise, at idle.

The correction for this involves removing the engine oil pan, cleaning and inspecting the pan sump and pick up tubes. The small rubber o-ring seals are then replaced on both the oil pick up and engine oil cooler. It is important to inspect the sump, and clean any oil sludge or debris from the oil pan area. As the 850 and S/V70 series engines use a two piece crankcase, you can not easily remove the main bearing caps for inspection, nor are the rod bearings readily accessible. The best test of the engine condition after this service is to use the mechanical gage again to verify pressure readings. On the car in question the engine oil pressure went from nearly zero at idle, to 35 PSI warm, and nearly 75 PSI at speed. This pressure in indicative of a engine in good condition, not having experience any wear in the bearing surfaces. Given the exceptionally low oil pressure, it is a testament to the robust design of the Volvo engine that no damage seems to have occurred.

VW Diesel TDI – Clogged Intake Port

July 26, 2011

Case Studies

Atlantic Motorcar Center

Low power, loss of acceleration on hills and under loads…all of these are symptoms of a clogged intake port on the VW 1.9 liter TDI engine. If you have 70K or more miles, and have not had a intake cleaning, chances are your intake port looks something like the one below. All the air for the engine must pass through this port, and as the port becomes clogged, airflow is reduced, the engine loses efficiency, and power output drops off. Imagine trying to breathe through a straw, and you have a good idea of how your engine feels. Since this is a gradual process, often taking years and tens of thousands of miles to occur, most owners do not notice the gradual loss of power. But they notice the difference after a proper cleaning has been carried out!

Port cleaning is not a simple procedure, but it is a necessary one. To do a through and professional job, one must remove the intake air inlet, often mistakenly called a “throttle body”, intake manifold, attendant hoses, electrical and vacuum lines. Properly done, it takes from 3-5 hours, depending on the degree of coking found. The cost for labor, chemicals and the required parts, is approximately $300-500, but the returns in both power and efficiency make it well worth the expense.

Volvo V70 – Power Steering Rack Failure – Water Entry

July 25, 2011

Case Studies

Atlantic Motorcar Center

A simple repair, costing less than $75, could have saved this owner from a nearly $1,900 repair bill, and potential accident. A protective rubber boot, one is located on each side of the steering rack, had split, and over several months, had allowed water to enter into the sealed and lubricated surfaces of the power steering assembly. The water quickly did its damaged on the polished and machined surfaces of the steering rack and pinion gears, as well as contaminating the power steering fluid system. The resulting damage caused in rapid wear to the steering rack assembly, excessive play in the steering, and a very hazardous driving condition.

To complicate matters, Volvo has updated the design of the steering rack, so the correction consists of replacing not only the defective steering rack, but also the pressure and return hoses, and the steering coupler. Prevention is always less costly than correction. Be sure that your steering rack boots, along with the boots used on the Constant Velocity (CV) joints, are inspected every service.

Audi A6 – Constant Velocity Joint (CV) Boot Cracking

July 24, 2011

Case Studies

Atlantic Motorcar Center

I should first mention that this is not an Audi problem, but is a concern on any front wheel drive vehicle, as well as some cars, Mercedes and BMW, which use CV joints on the rear axles.

Just in the nick of time, one of our techs noted the deep cracking on the constant velocity (CV) joint boots during a scheduled service of this car. The axleshaft is used to transmit force from the transmission to the wheel. The CV Joints allow the axle to pivot when the wheels are turned, and rotate at the speed of the front/rear wheels.

The CV Joints are covered with a protective rubber boot which keeps out dirt, and keeps the lubrication inside the joint. When the protective rubber boot splits or tears, this allows the lubrication to be thrown out of the joint, and dirt and debris to enter. A damaged CV Boot will lead to a rapid failure of the CV Joint itself, complete failure of the joint will prevent the car from moving. Often, but not always, a pronounced clicking noise can be heard from damaged joints. To minimize expense and CV joint replacement, these rubber boots should always be inspected each service for splits or tears, and replaced BEFORE failure occurs.

VW Jetta Diesel TDI – Dual Mass Flywheel Failure

July 23, 2011

Case Studies

Atlantic Motorcar Center

Great idea, poor implementation. Sometime back in the early 1990s Porsche tried this in the 911 series, it did not work out well then, and it seems not to have worked well now. The dual mass flywheel is composed of two parts, damaged with silicone to soften engine noise and impact shock during clutch engagement. Often, with older and high mileage cars, the silicone and damping material fail on the dual mass flywheel, resulting in engine noise, vibration, and excessive lash in the driveline when engaging the clutch. This vehicle experienced the failure at about 50K miles, really quite low as far as clutch life normally goes, but apparently quite common with the dual mass design.

The repair can be approached two different ways, taken from either a cost or durability standpoint. The costly method, and one which we feel not to be durable, is the installation of the same expensive dual mass flywheel unit, with the attendant failure problems down the road. We suggest the replacement and update of the complete clutch assembly to a solid flywheel design. The proper solid flywheel replacement has the approximately the same mass as the dual mass set up, so the exchange is all but transparent to the driver. Aside from the cost benefits, durability is of course improved with the solid design, as there is no longer any damping material to leak out, or become damaged. The photos below show the original dual mass set up, and the replacement, solid flywheel kit. Note the use of multiple discreet damping springs in the clutch disc on the solid flywheel unit, this takes the place of the damping material in the dual mass flywheel.

Audi AllRoad – Heated Steering Wheel Problem

July 22, 2011

Case Studies

Atlantic Motorcar Center

After no less than 5 trips to a local Audi dealer, and over $1,100 in repair bills, this car landed on our doorstep. Now, as a former AllRoad owner, I have soft spot in my heart for these wonderful cars, complex as they may be, so I viewed this as an enjoyable challenge! The problem, the heated steering wheel did not work. Yes, you read that right, some of the Audis do have a heated steering wheel, and as a Audi owner I can testify that its might nice to have on those cold Maine winter mornings.

On the Audi AllRoad, the steering wheel heater operates off the driver’s seat heater switch. Its actually a little more complex than that, as Audi also places the horn, Audio and Telephone control buttons on the steering wheel, as well as a locating a handy safety device, called an Airbag, there. Many of these signals run off a CAN (Controller Area Network) Bus system, to eliminate the number of wires needed. Think of the CAN Bus system much like a USB system on your home computer, a variety of different peripherals plug into a common set of wires, each addressable from the computer. Perhaps this sounds complex, but it is not easy to run a dozen or so wires to an object, the steering wheel, which is constantly rotating.

The long and short of the problem was this. Prior to the car arriving at our facility, the steering wheel had been replaced in a misguided attempt to correct a fault. After the 5 trips the dealer gave up and told the customer they did not know what was wrong with the car. Now we get stumped from time to time here, but you can be certain we never give up after charging you $1,100, we will work to a solution.

It took some time to properly diagnose, and in the case of most electronic parts, diagnostic time is always less expensive than just throwing a part at it. After removal of the radio and center console, to access the climate control unit and test the seat heater switches, our tech found the electronic “cassette” located in the steering column, to be defective. In fact, upon removal of the Airbag and steering wheel, we found a wire clearly broken away from the cassette contact, you can see this one of the photos. This is not considered a repairable fault as the Airbag safety system runs through the cassette, and the proper solution was replacement. Bottom line, its always less expensive to pay for diagnostic time than parts. Now the car is happy, and so is the customer!

Audi TT Quattro 1.8 Turbo – Defective Water Pump

July 21, 2011

Case Studies

Atlantic Motorcar Center

This car has was diagnosed with a defective engine coolant pump. Symptoms were overheating and noise from the front timing belt area. Disassembly of the front cover and timing belt, no easy task on at Audi TT, allowed for removal and inspection of the pump. As you can see from the photos, it is a bit of a process to access the pump, so be sure to always replace the timing belt and tensioner at the same time.

The timing belt, scheduled by Audi for replacement at 105K miles, has a history of failing considerably sooner, so consider timing belt service at 70 or 75,000 miles. The mode of failure with this pump appears to be a simple design flaw. The water pump impeller is made from a plastic material, the plastic becomes brittle with age and extended immersion in the hot engine coolant, and simply cracks apart. The defective pump, and pieces of the failed impeller, are on the left side of the photo, the new pump on the right. As this car is an aluminum alloy engine, Its always a good policy to flush the cooling system at least every two years, or 30,000 miles, and to use a quality antifreeze with corrosion inhibiters.

Volvo V70 GLT – Defective Turbocharger

July 20, 2011

Case Studies

Atlantic Motorcar Center

This car has was diagnosed with a defective turbocharger unit. Note the large amount of oil build up on the pressure side of the turbo, especially in comparison to the new turbo on the left. This oil is then drawn into the engine, resulting is severe smoking from the exhaust, high oil consumption, and even damage to the catalytic converter.
Note the Volvo replacement turbo box, we always use factory parts for reasons of longevity and proper fitment.

On late model car turbo failures are uncommon if the vehicle is cared for properly. Indeed, with proper care service life of 175 to 200K miles is expected. Turbo failures occur from two basic causes, lubrication failures, consisting of infrequent oil service, or incorrect grade of oil, and foreign material entering into the turbo and causing blade fracture. We strongly advise to never go more than 3-5,000 miles on conventional oil, and never more than 5-7,500 miles on a full synthetic. We recommended and use Castrol lubrication products in our workshop, either Castrol GTX, or Castrol Syntec.

Volvo S70 Turbo – Electrical Fault in Dash/Alternator Failure

July 19, 2011

Case Studies

Atlantic Motorcar Center

This car had an interesting story. The car presented with the charging light on, indicating alternator failure. The alternator light would flicker, turning on and off rapidly. Alternator failures are somewhat uncommon on the later Volvo S70s, but a charging system analysis showed that the alternator was indeed not charging under load, even when full fielded. 12 VDC was found at the field wire during the testing. We replaced the alternator with a Bosch remanufactured unit and then road tested the car. The alternator light came back on, but was steady, not flickering as before. We checked for voltage on the field wire, no voltage.

A check of the schematic showed that the field wire was powered up via the dashboard and indicator. We tried tapping on the dash and noted that the light would go out. We removed and inspected the instrument cluster, no fault found. The tech then followed the harness down under the dash and found a poor connection at a large multi-block connector. Correction of this fault corrected the charging issue and the new alternator will not fail or become quickly damaged like the former unit.

Audi S6 – Timing Belt Service w/ Water Pump

July 18, 2011

Case Studies

Atlantic Motorcar Center

The Audi S6 timing belt service does not normally require removal of the nose of the car, but in this case the silicone filled fan clutch was seized onto the idler shaft and could not be removed with the nose in place. 10 years and more recently time in the coastal environment seemed to have done its worse. To fully access the clutch required removal of the front bumper cover, radiator support and radiator, evacuate and recharge of the A/C system. As the engine water pump is driven off the camshaft belt, it is a good idea to replace the pump at the same time as belt service. All tensioner rollers should be inspected or replaced at the time of belt service.