This past 30 days we had 4 (four) 2.0T FSI cars back to back with cam follower failure at our shop. While technicians were working on them, I took a bunch of pictures and wanted put together a simple write up to show you guys how this failure happens, what the consequences are, the repair scale, and preventative measures.
This failure is not specific to modified cars with aftermarket high pressure fuel pumps, or other performance enhancing add ons such as software, exhaust, intake, larger turbos. 2 cars out of 4, were completely stock, maintained regularly by the dealerships till their warranty expired.
What are the symptoms?
Check engine light > “Low pressure in fuel rail” code
Poor running conditions
Loss of power
What cars are subject to this?
2005-2008 VW and Audis with 2.0T FSI engines.
Why does this failure happen?
Very simple. Combined with normal wear on the cam follower surface and the pressure from the high pressure fuel pump, the follower’s surface at one point gives up. In this case the cam follower was completely damaged:
It clearly shows the high pressure fuel pump punctured through the cam follower. This requires further inspection. This is the worst care scenario. In general we see excessive wear on cam follower surface, and minor scratches on the intake camshaft lobe which can be easily seen. If there is wear on the cam follower, we recommend visual inspection on the high pressure fuel pump, camshaft lobe and replacement of damaged parts.
Back to our specific case. This is how the high pressure fuel pump looked like:
As you can see the piston contact area is severely worn, and cam follower pieces are present between the piston and the spring. You can kiss good bye to this high pressure fuel pump, replacement is necessary.
Further inspection goes on with intake camshaft lobe:
The scratches on the camshaft lobe are obvious. Here is the disturbing part, see the cam follower pieces there?
This picture here shows the wear on the camshaft lobe as well (Intake camshaft is out of the cylinder head)
In a severe situation where the metal pieces are in the engine there are 3 options:
1. Replace the engine.
2. Complete disassemble and rebuild with new parts (replacing the engine is about the same price).
3. Carefully replace the parts and try to extract the metal pieces out of the car.
Option 3 is always the least preferred method, because there is only so much the technician can do to flush the metal parts / shavings out of the car.
This is one of the reasons why we see premature oil pump failures on FSI engines leading to catastrophic engine failures. Unfortunately, VW and Audi acknowledges the problem, but even in severe cases assumes the parts replacement would be enough to keep the engine in operable condition in its estimated life.
We choose to give the best of our knowledge to our client and have them make a decision based on their financial situation, and time frame.
Note: If the cam follower is not disintegrated, but there is normal wear, it is absolutely fine to proceed with parts replacement, followed by an engine flush.
We decided to take the work a little further down, and removed the oil pan. This way we could see if there are any metal shavings / pieces in the oil pan.
This is not part of the procedure recommended by the factory. However it gives us an opportunity to determine the severity of the damage. In this case, car came to us very soon after the check engine light was on, and started running bad.
Cleaned up the engine oil pan. Picture of the oil pump assembly:
Removed the screen on the oil tube to inspect metal shaving accumulation and clean up.
Assembly process is also tedious. This car was at the mileage where it needed a timing belt service. We proceeded with replacement of timing belt, tensioner, tensioner rollers, serpentine belt, and water pump.
New stretch bolts and everything from top to bottom is on factory torque specs:
Finally all the fluids are on the vehicle, codes cleared, and test drive. We invited the customer back after a while for a check up, and gave complementary oil change including BG engine oil treatment products. After 30 days, car is running very well.
How can this be avoided?
Simple. Frequent oil changes, and inspection/replacement of cam follower every other oil change or 10000 miles. We have been using Motul Specific 502.00/505.00 5W40 oil on FSI engines. It is a little more expensive than off-the-shelve Castrol or Mobil 1 but our customers reporting back with less engine noise, smoother running engine, and less oil burn (which is another case study material on B8 Audi A4s, coming).
About DBC Tuning:
DBC Tuning is the leading independent repair and service facility for Audi, BMW, Porsche and VWs in San Antonio, TX. We are a group of factory trained technicians with ASE certifications. Our shop is a Bosch certified service center. We invest in latest equipment and tools to provide a level of service exceeding dealership standards. We strive to better ourselves everyday, and we are committed to give 100% worth of your money back to you with our services. We offer 3 years 36000 miles warranty on all replacement parts. Our prices are very reasonable, but we price ourselves in selling SERVICE, not PRICE.
For any questions vw service related inquiries please call us at (210)3991172 or send an email to [email protected]