Abnormal Engine Noise in Audi A4 2.8 Q

jccai

Hi! My girlfriend has a 1999.5 2.8Q (sport,auto,bose, etc.). After getting the 22500 mile service, it started developing a metallic knocking noise in the engine bay. It sounded like lifter noise but it was intermittent. It was more obvious when the engine was cold. We took it to the dealer and they claimed they couldn't hear anything unusual. But I know the noise didn't used to be there.

Now a week has passed and the noise is becoming more pronounced. And it gets louder at higher rpm. She has an appointment with the dealer in a couple of days. Before the dealer feeds her the same "unable to reproduce" BS again, I want to see if anyone on this board has had similar problems. Maybe we can be armed with a bit more information before talking to the dealer.

Any help will be greatly appreciated!

jccai

My girlfriend took the car to the dealership today. They gave her a loaner. After letting the car cool off for the whole day (under hot Texas sun), the dealer called her and finally acknowledged the noise. Then he said they had seen quite a few incidents of this kind. That's funny, because the last time she took the car in, the mechanic swore that he couldn't hear any noise. Now all of a sudden it's a well known problem?

Anyways, she couldn't repeat to me the "technical stuff" the dealer told her. But the dealer did specifically ask her which side the noise was coming from. Apparently they only wanted to take apart one side of the engine (?). They told her it would take at least 3 working days to fix. She's quite upset about it.

I found another short thread in Maintenance & Repair archive regarding lifter noise in the 2.8 engine. But there wasn't any resolution to it.

car_hunter

I have a 92 Audi 100S. Everyday when I start the car in the morning, it starts rough (as if all parts are loose). Then in a few seconds when the RPM settles at around 800,, it gets a bit better but the noise (similar to a knock or a sticky valve lifter) is still there. So today I showed it to someone who said that it was quite common in many V-engines. He said that it is probably a sticky valve lifter that needs some cleaning. He recommended an additive that cleans the valve lifters and makes them run smoother and quieter. He also suggested using a 10W40 grade engine oil for the V6 engine. He says that heavier oil will improve lubrication and reduce engine heating. I don't remember the name of the additive he mentioned but I can ask him again. I will list the additive here once I find out. Hope this helps.

Mr_Shiftright

Probably the oil pressure relief valve in the cylinder head?

Let us know what the dealer says.

car_hunter

Here is what I found out but posted in another discussion:
car_hunter "1992-94 Audi Problems" Aug 11, 2001 6:30pm