Thread: TDI 300 NOISEY BELTS

Is the tensioner jumping up and down ???

You're going to need to clean the v grooves of the pulleys with a wire brush and maybe some carby cleaner. They have to be really clean to avoid squealing. After that, if the squeal is still evident, I have had success with using a clean rag on the grooves whilst the engine is running. You have to rig something like a big cranked screwdriver with the rag wrapped around it ( like a big cotton bud?) because using your fingers is really really dangerous. The rag supplies sufficient friction to clean whatever is on the rubber that is causing loss of friction on the pulley - and hence the squeal.

Avoid belt dressing at all costs - it just makes the belt worse - as does WD40.

or the main tensioner pulley needs throwing out, just replacing the bearing doesnt always fix it...

had to do it on a tdi i onced owned... replaced bearing and it did sweet FA. put new tensioner on, problem vanished.

Im with Inc...

The rubber bushing flexes forward so it is always forcing the belt slightly crooked against the pulleys.

When it gets really bad it runs the belt off.

Originally Posted by incisor

"the main tensioner pulley needs throwing out...

Had same problem at 300k. To double check, swap the belt direction & you should see a where the pulley scrubs across the belt.

Same problem recently, got an new tensioner for $85 off fleabay noise instantly gone..the seal between aluminum housings perishes and the metal rubs...

hey thanks for the replys,will try a new tensioner.
Cheers Bob

Had same problem with mine, drive ya nuts, idler bush gets a bit warn and gets itself outer line, I put a 1/4 moon shape bush behind mount to align it and had silence ever since