Mystery(misery?) vibration, I am determined to find a solution.

[Dragonslayer182]

I have a little bit of vibration in my sedan, do you have a problem with squealing coming from the engine? It mostly happens during squealing, and so far neither a belt replacement nor an alternator replacement (It was going bad) has remedied to problem, although they did both stop the squeal for a few weeks at the most. I also notice symptoms of voltage drop when it squeals. (Slightly slower windshield wipers, slightly dimmer headlights)

[seatech30]

Originally Posted by Dragonslayer182

I have a little bit of vibration in my sedan, do you have a problem with squealing coming from the engine? It mostly happens during squealing, and so far neither a belt replacement nor an alternator replacement (It was going bad) has remedied to problem, although they did both stop the squeal for a few weeks at the most. I also notice symptoms of voltage drop when it squeals. (Slightly slower windshield wipers, slightly dimmer headlights)

Does the squealing happen when the car is on without A/C, and does turning the A/C make it worse? My belt used to squeal on cold days, particularly when turning the car on. For me that was just a loose belt. If the squealing is consistent and predictable, I'd take the belt off and see if the squealing goes away. If it does, (car off) check the pulleys on the compressor, hamonic balancer, and starter for any give or wiggle. It's hard to do. If the squealing still happens without the belt, then you may have another issue that I can't guess at.

The vibration for my two yaris is pretty noticeable, likewise when shifting into N, there's a significant reduction in vibration transfer into the cabin. When shifting back to D or R, there's a bit of a jolt as the transmission engages. As for the Corolla, I haven't played with it much, but it is much more subtle, mainly noticed it because I've been obsessing over this issue with my other cars.