Intermitent Clutch (i think) Squeal

[CTScott]

Originally Posted by alex22808

Just took a look at the belt. It seems fine. I checked the grooved side and it fine ie the grooves were all there. it also felt pretty tight, so it seems unlikely that the squeal is caused by it being loose.

Is there any other options? i am no expert, but the belt seems fine to me. Again, thanks for the replies!

The happening most when it is cold/damp really points to the belt. The Yaris is tricky with belt tightening because it does not have a screw tension. Rather you have to pry the alternator away from the block and then tighten the bolt, so there is far less precision to tightening it than with a screw tensioner. Some brands of belts are better than others when it comes to squeaking. I have found that Dayco belts are the worst with the Yaris, where short of overtensioning the belt you can't make them stop squeaking (and that's when they are only a month or two old).