Imol8tor

Hi, new user here, I've recently acquired an A4 B5 1998 1.8T and from the off she's had a screeching alternator belt, so I sent the wee lass into the shop to have a new belt fitted;
Two belts later and no squeaking but now I've noticed she's making a rattling sound, very much like a cover rattling and I've noticed the tensioner moving slightly too;
I've read it could be anything from oil pump, timing belt, water pump, the tensioner itself or even a loose cover but nothing definitive, any help would be gratefully accepted.

morpheousx

I can tell you that your serpentine belt tensioner, needs to be replaced if its "moving".

It's suppose to be still, if its moving and make a noise, its time for a new one.

I know because i replaced mine with a new one as it was shaking and making an awful loud noise.

Imol8tor

Many thanks, I'll inspect the old one in the next few days, seems fairly straightforward removing it, I'll report back with the results of a new fit.

Imol8tor

Well the saga continues, changed the tensioner and I've still got a rattle, so back into the shop she goes for further investigation, I'm still thinking one of the pumps is on the fritz;
Many thanks for the help.

twentysevenlitres

Add the alternator to your list too, they make a loud rattling nose when the bearings start to fail. To test, remove the belt and spin by hand - it should be totally silent. If it makes noise (even if spinning well) its probably on the way out.

Also, if you've got climate control, try disabling the airconditioning (ice crystal logo button) and see if it quiets down (in which case its the compressor - and leave it disabled until you replace it).