Alright so im getting this noise that i cant really figure out so let me explain it to you:

It sounds like a chatter at times and at other times its a little lighter sounding (id say it sounds like tapping or blowing on tin foil but a little deeper sounding than that). It happens in first through third gear when im accelerating around 1/2 throttle and above. I can be at higher rpms and hit the gas hard and it will chatter and then when i let up it will stop and then as soon as im on the gas again it will start again. Usually when im in second and flooring it, it will stop once i get past 5k.

There is no noise when i rev it in neutral.

I dont think its turbo nosie because when im in 4th gear and flooring it, at full boost (not chipped, so about 9-10 psi) there is no noise. It will make this noise at 0 boost too.

Both CV joints are new, and the (manual) tranny fluid was replaced a little while ago, with Mobil 1 full synthetic 75w-90, and same for the rear diff.

I wouldnt say the noise happens any more or less depending on the pitch of the car or what direction im turning.

It still runs smooth, there is no roughness when it chatters.

Pre 1999 A4 1.8T 5spd, 140,000 miles

So, are there any ideas? Exhaust or transmission or something, anything i can check to rule anything out.

Oh and the clutch feels fine and the shifts are still smooth.

Thanks

 

Bump....

 

So it only makes noise when the car is moving, correct?

 

Yep. Not moving and revved either, it has to be in gear.

 

Since it only makes this sound when you are moving in gear/engine is under load, I'd have to think it's an exhaust leak close to the engine. Exhaust manifold/turbo/cat/downpipe gasket could be leaking and would make a ticking/tapping/chattery type sound.

An exhaust leak is a lot harder to hear in neutral/engine not under load if it's very close to the engine, unlike a sputter sound you'd get if it were further back around the mid pipe back.

 

You can rule out your center drive shaft. Blauparts has a write-up on Quattro noises.

http://www.blauparts.com/audi/audi_d...pair_kit.shtml

 

Alright thanks for the help guys, ill try and take a look at the exhaust sometime this week.

 

You say there is no noise when in neutral. Is that neutral with the car not moving or with the car moving? Reason I ask is with it sitting still the driveshaft is not turning. You might look between the heat shield and the drive shaft to see if anything might be in there rubbing the shaft. Believe it or not I had a cat crawl up there and I had a hell of a time finding that noise. Its just a thought, If its a weird problem at one time or another I have run across it.

Good Luck...

 

Uh, was it alive when you found it...?

At the shop I used to work at, we had a request to remove a very destroyed, smelly racoon carcass from a Boxster engine bay... but it certainly wasn't making noise!!

 

Ahhh, No the cat didn't make it through that ordeal. Ends up it was his bones hitting the center section making the strangest sound I've ever heard. I actually had to put in on a rack with somebody in the drivers seat to start the car and run it through the gears and we finally found the problem. Poor Kitty..... LOL!