DoubleOS4

I took it to the dealer and they were unable to replicate the noise. So I went back to the dealer and took the technician out with me and caused the car to make the noise. He thought it might be the flywheel or pressure plate.....(too bad my A8 isn't a manual). Here is a description of the noise.

The engine speed needs to be between 1400 and 1600 RPM with little or no acceleration. It really likes to make the noise when the car is coasting down in speed. I originally thought it might be the tranny, CV joint or wheel bearing. However, it will make the noise in Neutral, all I have to do is rev the engine to 1600 rpm, left of the gas and the droning sound/slight vibration on the accelerator pedal is felt.

I am hoping someone else has had a similar problem. The car is 1999 A8 4.2 with 32,000 miles.

Any suggestions/help would be appreciated. The car is still under warranty, I am just trying to help the dealer solve the problem.

PaulW

I find it hard to believe that it is the flywheel or pressure plate, does the car even have a pressure plate? That's for a manual transmission car, correct? It's part of the clutch, the part that bolts to the flywheel.

Maybe it's some kind of electronic glitch causing one or more cylinders not to fire or fire incorrectly. Did you pull the codes for the transmission and engine? If so, were there any fault codes?

Don't hand over that car to a dealer until you have troubleshot it, it sounds like it could be a long process. If you drive it and figure it out (along with a troubleshooting/repair plan) before hand, you have a higher probability of fixing it the first time.

pw

DoubleOS4

Yes, the above mentioned components are for a manual transmission.

I have not pulled engine codes because I do not yet have the tools.

The vehicle is still under factory warranty, so I am hesitant to do too much on my own as to not void the warranty.

Thank you for your input.

John

skiracer

Since the vibration only occurs in a very narrow RPM band, it indicates to me that it is something that bolts onto the engine and has a natural resonance that is excited by the vibration of the engine at these RPMs. Have the mechanic check EVERYTHING that is directly bolted to the engine (at the connect point to the engine as well as all other bolts in the assembly). I can't think of anything else that would behave that way (over such a narrow RPM range). Let us know what you find, if anything.

D3AeighT

I think you indicated you had it in for service ( under free period ) and you described it to them and thus you must have them write up on the work order. "Techy" said it sounded like so & so. So what did they do?..just let it go as unable to replicate...doubt that since you got them to hear it...replicate it. They should have made a call Audi Tech Op's, for assistance. You need this documented as I would think you are running out of time to fix your issue free....3 years must be coming up quickly, but good miles 32K. It is their problem to resolve.

PaulW

Maybe a motor mount going bad?

DoubleOS4

A bracket or motor mount are great ideas, thank you!

icedillon

I have been told that could possibly be an issue with the balancer shaft/belt - I have the same problems!!!