Loud belt squeal when cold

[Bikerboy89]

Hello I have never had a car do this so it's a little surprising my 2015 yaris automatic is with such low miles (57k). If it's squealing for a while after it starts (like 10 seconds) does it mean it needs a new belt or is there a way to tighten it up a bit? It only does this after a cold start and it's already in the 30s here in Michigan.

[WeeYari]

Typical. Needs a bit of tightening.

[Bikerboy89]

Originally Posted by WeeYari

Typical. Needs a bit of tightening.

Thanks I see on the alternator the bolt on top with the groove. Is there another bolt to help loosen it?

[WeeYari]

Loosen the top alternator mounting bolt. Using a small pry bar, or similar item, CAREFULLY pry alternator forward. I say carefully because it is very easy to inadvertantly damage the OCV mounted in the engine block behind the alternator. There are numerous threads on here with people questioning 'what is this thing I just broke?' as a result of trying to tighten their belt.

Also, before loosening the bolt, on the slotted bracket, mark the current position of the bolt so you can monitor how much you are moving it.

[Bikerboy89]

Thanks a lot!

[dogsridewith]

Need to loosen both bolts. A 13-14 inch channel lock plier works better for tightening than a pry bar, and isn't near anything it can hurt...one jaw on curved slot bracket end, other jaw on alternator at bolt boss.

[Bikerboy89]

Thanks sir! After reviewing the service manual I realized I would have to loosen both bolts. I did just use a prybar I only moved it a little bit and the squeal is gone for now. So you know if there's a position on the bracket that's considered too far where the belt would need replaced rather than just tightening more? Also when summer comes back around you think I'll have to loosen it a bit?

[WeeYari]

First off, you do not need to loosen both bolts. Several years ago Toyota released a TSB regarding belt tension. In the outlined procedure to mechanics it specifically stated loosen top bolt only. The alternator will pivot on the lower bolt without loosening which is great since it is a pain in the ass to get to with your average set of tools.

No, there is no point on the slotted bracket which indicates too far.

No, you will not have to loosen it in the spring.

[Bikerboy89]

Thanks for the information. The only reason I ended up loosening the bottom bolt too was when I tried prying it it wasn't moving and I was worried about snapping something off. Maybe I was just being too timid with it because I read elsewhere online also, someone broke theirs off.

[WeeYari]

http://www.yarisworld.com/forums/sho...31&postcount=1

[Leegamer]

Originally Posted by Bikerboy89

Thanks for the information. The only reason I ended up loosening the bottom bolt too was when I tried prying it it wasn't moving and I was worried about snapping something off. Maybe I was just being too timid with it because I read elsewhere online also, someone broke theirs off.

happened to me earlier this year, lol.

[dogsridewith]

Shop manual says loosen both bolts. Yes, on many random cars of all types the lower bolt is loose enough that you only need loosen the upper one for belt adjustment. On this new-to-me 2007, that's what I did first. But the alternator position was just frozen until I loosened the lower bolt. Used a correct sized socket on a 3/8 drive ratchet wrench w/ a piece of one-inch aluminum tube as a cheater to gain a little length...just enough room for one click per rotatation. (Best might be a long enough 12 point box end wrench w/ the right bend for access.)

Now that I know a tool to use, I do tighten the lower bolt. Also can see why Toyota dealers would rather prefer to avoid those steps to save time by leaving the lower bolt sorta tight.

The manual instruction to use a pry bar but w/ care not to hurt that part is bad advice...many or most people doing the job will have trouble finding the vulnerable part.