ulm210

Hello All, new here. I just bought a 2008 S6 with 97k miles. From the look of the Carfax the first two owners accounted for 85k miles and took the car to Audi for service on schedule. The third owner, who I bought it from, did their own service. Before I bought it I took it to Audi for a PPI. The worst thing they found was some oil on the front and bottom of the engine.

The current owner did not do a carbon cleaning, and the maintenance records on carfax do not describe a carbon cleaning with either of the first two owners. There were recalls, and miscellaneous visits to clear codes, etc, in addition to the scheduled service.

So, I assume that it is due for a carbon cleaning and that when they are in there they can attempt to identify the oil leak, which, according to the online forums I have read, have a high probability of being resolved with new o rings and valley pan gaskets. Via google search and yelp I found an independent mechanic who has a very professional looking shop and online presence. He claims to have worked at Audi Service for 15 years and has been in business for himself as an Audi specialist for about 5 years.

I talked to him on the phone and discussed what I wanted done, and he sounded like he knew what he was talking about when describing the process and what was involved. I told him I wanted this car to be my year round daily driver and was looking for professional advice on what needs to be done to get the car in excellent running condition. He recommended new coil packs and an injector service due to age and mileage. I also asked him to do an oil and filter service just to get maintenance records at a baseline. He quoted just under $2k for everything,edwhich in my mind seems reasonable.

He called me after he got a chance to drive the car and then start inspecting the engine bay to say the breather hose is leaking, that it was difficult to remove the oil fill cap due to the vacuum. He never once says anything about the car not performing well or that anything seemed "off". Then throughout the day he sends me pictures of conditions before and after cleaning. So far so good. Then he sends a picture of the manifold on a work bench and in his hand is what he says is an air flap that fell out when he removed the manifold. He is charging me $2300 for a new one (no labor charge).

Here is my question: I drove the car daily to and from work for a week and never experienced any malfunction, misfire, hesitation, or noise, everything I have read that are the symptoms of a stuck or failed air intake flap.

Additionally, if the flap was broken should it have been discovered during the PPI at Audi, either via ecu failure codes or a typical operation analysis?

Finally, for a mechanic who claims to have 20 years experience with Audi, should he have suspected a problem during the test drive that was this catastrophic?

Something just seems amiss, or is it really that difficult to diagnose a failed intake until it is removed and inspected?

Thanks for any information or experience you can share.

-Dave

WolfieVonMat

You'll need to replace the intake manifold on it at some point if it wasn't done by the previous owners, unfortunately. Sometimes the flap can be heard banging around on cold start, or at low RPMs. It does not always trip a code, but I understand you can feel the power difference in the low end. Carbon buildup may have similar affects on the power band, and it's tough to know the difference if you haven't driven a few of the same model. An experienced Audi tech should know what to listen for, and know it's a known issue on these motors. Audi should also have service history records to determine if the manifold was already replaced.

The intake manifold isn't all that catastrophic, and it's not always easily detected. It's just a very expensive part. If you only paid $2300 for the replacement manifold, I am guessing you got the JHM version and not the OEM version. Make sure it was replaced with the newer design that got rid of the plastic flaps, otherwise you will just have this same issue down the road.

When I was shopping for my S6, I specifically looked for cars that had the intake manifold already replaced.

Having this work done now is definitely for the better.