Help me anticipate this repair? My '06 Scion with 120K has an occasional squeal that I am sure is the serpentine belt - it’s repetitive at the right frequency that goes up and down with engine RPM whether car’s rolling or not, and often it goes away the moment I turn the AC off, or stop trying to turn the steering wheel while standing still. And sometimes if I am turning the wheel, it will do this turn-grab-turn-grab thing like I’m making the power steering pump pulley slip. I’ve tried belt dressing spray a couple times, and it has never done it within a few days of that, but then it sometimes goes a week or two without doing it anyway.
But the weird symptom that does not fit is this: occasionally when this starts, the engine bogs down a bit, like it’s suddenly being heavily loaded. This makes me suspect that one of the things the belt drives is failing in a way that makes it hard to turn for a few seconds. This usually doesn’t happen, but a few of the times it’s squealed, it has. I presume this failure is only evident once in a while.
I haven’t noticed anything else. Yeah, I think it’s likely I need new new belts (there seem to be two). I’m just wondering if I need something else replaced, and if its malfunction is very sporadic, might the shop not figure that out?
Are there any particular clues I can look for, or things to check during those brief spells (much less than a minute) when it’s squealing?