Screeching belt noise

millwalls

I own an old Mitsubishi Colt which gives out a screeching noise at idle and very low speeds (parking, traffic lights, etc). The noise only happens if the a/c fan blower is on, not otherwise. This has been going on for more than a year now.

Any thoughts on what the issue might be?

Mistral001

The alternator belt might need tightened or replaced.

AdrianC

The belt's worn, loose and the pulleys have got glazed. Basic maintenance.

New belt, if it still slips, give the pulleys a proper clean. Next time, replace it earlier.

millwalls

Thanks!

I have been having battery issues as well (draining too quickly when stood) even after replacing the battery as suggested by a mechanic. Could that have anything to do with the alternator belt as well?

Mistral001 wrote: »

The alternator belt might need tightened or replaced.

DoaM

Yes it could - in fact the alternator itself may be on the way out (e.g. sticky to rotate so increasing the load on the belt/pulleys).

millwalls

Oh dear, I should have checked on this forum many months ago!

The battery issue has been driving me nuts, it all makes sense now. Will get the belt and alternator checked asap.

Thanks for all the advice, it is much appreciated!

motorguy

As per what Adrian said, but i would also add it could be the tensioner.

Replace belt, if that doesnt cure it replace tensioner and belt.

The_Rainmaker

And once you have checked the belt and the alternator if there is still a problem you are looking for a drain on the electrics. But you can cross that bridge if you come to it.