Belt noise at idle?

[senna9113]

When cold & sometimes at a standstill (idling) my 2002 996 TT makes a strange belt type noise from the engine bay. The main drive belt was changed recently and i found no play in any of the pulleys. The car was in to the OPC for a Tiptronic service and after that there was no noise - it has now started coming back more regularly (this may just be coincidence)

Strangely if I turn off the automatic air con the noise goes away? Could it be the tensioner giving up or does anyone have any other bright ideas.

[jpflip]

Not too many people to guess that one. Since the problem go away with the a/c off it can be the magnetic clutch on the a/c pump....But of course it is only a guess because when you put the a/c on you are also stressing the belt and the rollers. Macster on another forum had problems with noise from the belts. Look at Rennlist, / turbo / 996 turbo and do a search for "dry bearing noise" coming from top....

[jthailer]

I had a similar thing happen on my 2003 Boxster S. Soon after changing the belt I started getting a squeaking sound after the car was warm.

I took the new belt off and put the old belt back on and the noise went away. Now I just keep the new belt in the spare tire pouch just in case the old belt fails.

It seems like the new belt is just a little bit wider and must be rubbing against something. It is a Porsche belt that I purchased.

[pmfakelly]

I have this same problem, it has been worked on by on opc and they replaced both condensors and aircon pipe with a re gas after each repair. that was 4 months ago and the noise is back. the noise is only there when you have the ariconditioning turned on. It was explained before that the pump is labouring with no gas as it had leaked out over time.

Any comments greatly recieved as i think that this is not an uncommon problem.

[wvicary]

Also inspect the slip pulley on the alternator.