Accessory noise please advise!!!
 

Hello my fellow Audi (best cars ever made....ever) friends!

My A6 recently sprung a sound that has me scratching my head...

When I start the engine cold with the A/C on it makes a constant clicking sound like a bad accessory bearing or something, it continues to make the sound for the first 5-10 minutes of running. If I turn the A/C off the sound disappears.

Additionally the pitch of the clicking seems to change while turning the wheels back and fourth, and the sound seems to be coming from around the PS pump. I thought it may be the A/C clutch bearing but there is absolutely no sound coming from the compressor area.

I have no decrease in A/C efficiency or any noticeable change in power steering output.

So...engaging the AC while cold produces a sound from the top center of the engine area around the PS pump and changes pitch when turning the wheel. I'm thinking that the extra engine load is the reason for this

Please help if you have experienced something similar to this its driving me a little bonkers lol.

p.s. I will try to post a video of the sound to help out.

Come on!! No love on this one?????

Have you tried topping off the power steering resivior (with the correct mineral fluid) then turning the wheel lock to lock with the cap off? That will get all the air out of the PS system, so if thats the problem it should cure it. The PS fluid is mineral based which will evaporate over time. You can also try spraying PB blaster on each pulley one by one and see if the noise goes away.

hi auditech, Yes I did do that and with the Audi/VW mineral fluid. Is it possible that the sound is the cam chain tensioner going? would this sound come and go with the AC compressor load on the engine???

Have you tried starting the engine with the ac OFF? After the engine warms up turn the ac ON..what happens?

If there isn't any sound coming from the AC compressor, it probably isn't related directly to the AC. I agree, it sounds like something to do with the engine load. Maybe you have a tensioner that is on the verge and once it warms up is back to normal.

I have tried a couple things like that, like waiting until the engine is warm and it doesnt seem to be as bad. Im letting the engine cool down and about to take a video ill get it on, however I did just remove all the covers and spray pb blaster on the pulleys so lets see what happens

Ok I made a video, after watching I realized I should have just shut up and not talked so much so you can hear the noise more than my voice lol. but I think it gets the point across.

http://www.youtube.com/watch?v=9qm4t1XiPpY

The video is kinda rough, the only thing i can hear is like a clunky/tapping type noise
which is usually the cam tensioner, but again its hard to tell. It would be best for you to take off the front bumper and put the lock carrier in service position (move it forward basically) so you can get a better look at whats going on. You can also try the old school trick of putting a long screwdriver to each componet and listening to it with your ear on the screwdriver. Kinda like a poor man's stethescope.

Oh, and when was the last time you changed your timing belt and water pump?