Hello- I have a '98 A6 2.6- I had my timing belt, tensioners, water pump, etc... Replaced a year ago- Also, just did a tune up (new wires, plugs and PVC hose) - My issue is I am hearing some type of rotational noise which I think is coming from the front passenger side of engine. I was originally thinking it was a valve noise but I have read that valve noises go away after the oil has warmed throughout the engine- Anyway, does anyone have any suggestions? I am hoping it is not a timing belt pulley- Also, what are my risks (keep driving) and is there a way to test or check to determine where and what is making this noise-

Note: I found a thread on "pulley noise" but am not sure if the issues are same-

Thanks in advance for your help!

 

Too add to this- my car sounds like diesel at idle

 

If it sounds like a diesel at idle i would first have your oil pressure checked to make sure that is up to par.
If thats ok its probably your hydraulic cam adjuster on the passenger's side.

 

Thanks auditech79- "Engine is 2.8" I am sure you knew that-
1) What causes low oil pressure (oil pick up unit, etc..)-I had a compression test back in June and it was fine-
2) If it's my hydraulic cam adjuster what is involved to fix and what should Iexpect to pay for this job- I am hoping it doesn't involve removing the timing belt

I have an appointment next Monday to get this checked and just want to know what I am looking- Also, are any of these DIY and should I be driving with those potential risks?