Drive belt squeal at idle.

[junorico24]

OK so I changed the belt . I tightened it up, but have a squealing at idle. It goes away at cruising speed when the car is running. When the car is running it's fine.But it randomly comes back at idle, not always but it squeals when i come to a full stop.It doesn't always do it. I have the crappy dayco brand belt.

HELP...

[CTScott]

Typically that means that it either is still not tight enough, or that while it was initially squealing the contact surface of the belt glazed (where the friction of it slipping caused the surface to melt enough to become too smooth to grip on the pulleys).

I have a Dayco belt on my red Yaris, that I grabbed because it was the only thing in stock at the store that I grabbed it from. I have had to tighten it three times since the initial installation.

[junorico24]

Originally Posted by CTScott

Typically that means that it either is still not tight enough, or that while it was initially squealing the contact surface of the belt glazed (where the friction of it slipping caused the surface to melt enough to become too smooth to grip on the pulleys).

I have a Dayco belt on my red Yaris, that I grabbed because it was the only thing in stock at the store that I grabbed it from. I have had to tighten it three times since the initial installation.

The belt stopped squealing for now. My only concern is if the alternator charging the new battery. I hope i have the right tension.


Thanks Scotty mate.

[hw6515]

Though the proper tension is required, did you check the pulleys for damage?

Specially the water pump one, I found mine damaged while replacing the belt.

If you used WD-40 in the alternator lower bolt, I suggest spraying the area with a mild degreaser then flush it with water.

[junorico24]

Yeah, my water pump pulley is glazed it looks like that pic.Thanks for the info

man. How much does a new one cost?

[hw6515]

Originally Posted by junorico24

Yeah, my water pump pulley is glazed it looks like that pic.Thanks for the info

man. How much does a new one cost?

Close to $40 each.

Got the Water pump and the pulley from Amazon.

http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

[The Critic]

Some glazing is normal. It is hard to tell from that picture due to the reflection.

I just installed a Dayco 5040465 today and had no problems at all.

From past experience, it is not uncommon for aftermarket belts to stretch a bit more than the OE belts. Therefore, it may be necessary to tighten them a hair tighter than required. The revised spec for the 2007 Yaris is 10-11mm (used belt), not the 11-14 that the manually originally specifies. Since you are using an aftermarket belt, I would tighten it a bit tighter...probably 7-10mm.

This is how I tightened it: use a prybar and pry HARD between the engine mount and the reinforced area on the alternator. If you look in this post, the "reinforced area" that I am referring to is the rounded area that sort of sticks out: http://www.yarisworld.com/forums/sho...85&postcount=1

If you use a very long prybar (24") and pry hard against the areas I mentioned, while still holding your prybar, fully tighten the 12mm bolt at the top of the alternator. This should fully secure the alternator in the position that you desire. Then f/u by tightening down 14mm bolt at the bottom.

If you do this with a new belt, the belt should have very little deflection. After the 10-15 min run time, you should feel a small amount of deflection (7-10mm) which is just a hair tighter than what Toyota suggests...and your noise should go away.

[hw6515]

Yeah the pic is not good, but is not glaze, the belt wore the finish and scored the pulley noticeably.

This is a pic of the new one.

[junorico24]

Yeah, good idea. Pry bar the thing tight. I tried to pull it real tight. But it still squeals.

[junorico24]

Originally Posted by The Critic

Some glazing is normal. It is hard to tell from that picture due to the reflection.

I just installed a Dayco 5040465 today and had no problems at all.

From past experience, it is not uncommon for aftermarket belts to stretch a bit more than the OE belts. Therefore, it may be necessary to tighten them a hair tighter than required. The revised spec for the 2007 Yaris is 10-11mm (used belt), not the 11-14 that the manually originally specifies. Since you are using an aftermarket belt, I would tighten it a bit tighter...probably 7-10mm.

This is how I tightened it: use a prybar and pry HARD between the engine mount and the reinforced area on the alternator. If you look in this post, the "reinforced area" that I am referring to is the rounded area that sort of sticks out: http://www.yarisworld.com/forums/sho...85&postcount=1

If you use a very long prybar (24") and pry hard against the areas I mentioned, while still holding your prybar, fully tighten the 12mm bolt at the top of the alternator. This should fully secure the alternator in the position that you desire. Then f/u by tightening down 14mm bolt at the bottom.

If you do this with a new belt, the belt should have very little deflection. After the 10-15 min run time, you should feel a small amount of deflection (7-10mm) which is just a hair tighter than what Toyota suggests...and your noise should go away.

Thanks so much man...The reinforced area is left side of the bracket near the belt side?

[The Critic]

Originally Posted by junorico24

Thanks so much man...The reinforced area is left side of the bracket near the belt side?

It is the part of the alternator that sticks out and is nearest the top bolt on the engine mount.

[UberSilver]

Originally Posted by junorico24

Yeah, my water pump pulley is glazed it looks like that pic.Thanks for the info

man. How much does a new one cost?

rockauto has them for $33.

[junorico24]

Pry bar ftw..It seemed to do the trick.Success! Thanks critic..

[jpmck03]

Originally Posted by CTScott

... I have a Dayco belt on my red Yaris, that I grabbed because it was the only thing in stock at the store that I grabbed it from. I have had to tighten it three times since the initial installation.

^ That's been my problem... Apparently Dayco belts are like rubber bands, they love to stretch! I think I've had to tighten mine about 3 times so far as well.

[The Critic]

Originally Posted by jpmck03

^ That's been my problem... Apparently Dayco belts are like rubber bands, they love to stretch! I think I've had to tighten mine about 3 times so far as well.

How tight are you tightening yours? I tightened the belt until it has just a hair of deflection.

[harda toenail]

Toyota installed a new one on mine when I brought it in for a water pump. I had to tighten it a week later

[bankrobber]

Same problem here. I installed a new Dayco belt from AutoZone because it was lifetime warranty. Within a few weeks it started slipping at start up. I was lazy and let it go awhile. I finally tightened it and have had to tighten several more times. Starting to slip again. I will never buy a Dayco belt again. I will probably replace it with a belt from toyota soon

[yaris4062007]

Only yaris has this problem :(. My other cars never had this problem. I have changed twice with new belts it squeaks alot ;(