js42

1999 A6 Avant Quatro - 2.8 106,000 miles
Timing belt done around 98k

I did an oil change about two weeks or so ago and drove the car for a week with no problems. Then parked it for about a week then started it up fine. About 30 miles later i stopped it went into a store for a half hour and when i cam back out it started making an odd noise. There seem to be 2 different sounds. One sounds like valve rattle mainly from the passanger side it seems. The other sounds like a low rotational wirring. Similar to a pully bearing going out but not as grinding or high pitched. I rechecked oil and it looked good but i drained it anyway and put new in and nothing changed. No warnings or check engine lights are on.

Any ideas?

I also want to pull the valve covers if for nothing else then just to check it out. Is there much ionvoled with that?

JerzyBoy973

What oil are you running?

js42

Synthetic 5w30 valvoline i think.

dr.bombay

I had a (possibly) similar sound. I ruled out the timing belt/tensioner b/c it had recently been reaced. I noticed that it correlated with engine temp and I started worrying that it was valvetrain related. Turned out to be the alternator. you can check by pulling the serpentine belt and seeing if the sound goes away.

JerzyBoy973

I think people are having better luck with the 0-40. But I have seen a lot of people running the 5-30. maybe you should look into oil type? There are quite a few oil threads on this forum and others.

js42

I'll try both of those. I was thinnking that maybe the synthetic was a causing some of the noise. I hate to drain it again but a quick switch back to standard is still cheaper than having the shop check it out.
Thaks for the sugestions, I let you know what I find.

JerzyBoy973

i wouldnt run standard. I was just referring to oil weights.