New serpentine belt squeals... alignment issue?

I just replaced the serpentine belt on my car because the old one was squealing. The new one squeals too, though less than before. I suspect it’s an alignment issue. I marked all the bolts with chalk and tightened everything back to spec. Any tips on how to fix this myself?

Have you checked all the pulleys? Sometimes even a slight misalignment can cause the squealing.

Bennett said:
Have you checked all the pulleys? Sometimes even a slight misalignment can cause the squealing.

I used a ruler to check alignment, and everything looks straight. Could it still be off even if I don’t see a wobble?

Is it a stretch belt or one with a tensioner? If it’s a stretch belt, it might not be tight enough.

Roman said:
Is it a stretch belt or one with a tensioner? If it’s a stretch belt, it might not be tight enough.

It’s a stretch belt. I tightened everything as much as I could, but it still squeals at idle.

Does it squeal more when you turn the steering wheel or under load?

Tay said:
Does it squeal more when you turn the steering wheel or under load?

Yeah, it gets worse when I turn the wheel to full lock, especially when the engine is cold.

Check if the large pulley with the 19mm bolt is misaligned. It might cause sideways tension on the belt.

Jane said:
Check if the large pulley with the 19mm bolt is misaligned. It might cause sideways tension on the belt.

Good point! I’ll check that and see if I can align it myself. Thanks for the tip!

I had a similar issue, and it turned out to be a worn pulley causing the squeal. Replaced it and no more noise.

Jony said:
I had a similar issue, and it turned out to be a worn pulley causing the squeal. Replaced it and no more noise.

That’s a possibility. I’ll take a closer look at the pulleys to see if any are worn.