Serp. Belt or Pulley? A light squeal, not loud.

[SumpChump]

Toyota 2.4L 2AZ-FE with 130k, fairly well maintained,inspected adult driven on road and not abused. Last water pump at about 70k. Running ok, no seeping, no over heating, no codes, no undercharging.

I get a light squeak/squeal at startup for about 30seconds (then trails off to imperceptable) and does it after 7 or more hours of sitting. Only when damp out, ambient temp has no effect. Cold and dry ... No squeal. Hot and dry.... No squeal. It does not do it when restarted or when dry climate and I cannot artificially create the squeal by revving it on a dry day. Once tha engine is warmed, even on a damp day... No squeak at startup.

It's not really a squeal as one might hear from a beat to [censored] 1996 Cavalier. Nothing like the old V-belt, super loud "reeeeeeeeeeeet" which goes forever amd ever.. Nope.
Its a high pitched but NOT high volume squeal. Maybe I should have waited to post until I have daylight for a video to help.

Belt runs straight and true, no side to side walking or wobble, no flapping up or down. Belt is not "wet", i have a hood on the vehicle, car has not been driven through flood waters. Lol

Maybe I am over thinking this but ..... I cringe but.... I think maybe these are all signs it is the 3inch round idler pulley having a bearded ng problem at the engine rear? And the freaking thing is like 1 inches from the passenger side "frame"rail. Tight workspace... Maybe they get at it from underneath?

What are your thoughts... Belt or idler/other pulley?

 

[HerrStig]

Spray some water in a fine mist on suspect locations and see if you can make it stop.

 

[JMJNet]

Try tightening the belt a little more?

Some brands are just a little bit more squeaky than others.
I have used several brand, the best so far is Mitsuboshi which is the same as you can buy from dealership.

 

[SumpChump]

Originally Posted By: JMJNet
Try tightening the belt a little more?

Some brands are just a little bit more squeaky than others.
I have used several brand, the best so far is Mitsuboshi which is the same as you can buy from dealership.


Auto tensioner.

I also hear Gatorbacks are fantastic? But I am an OEM fan usually.

I'll have to try that 'water spritz test' to quiet the light squeal. Going to be plenty moist tomorrow after tonights rains so I'll try to get a startup video posted.
I almost wonder if the stationary idler pulley "rusts up" over night when humid and a has to "wear in" when first started after a 6-7 hour sit.

 

[mclasser]

Originally Posted By: SumpChump
Originally Posted By: JMJNet
Try tightening the belt a little more?

Some brands are just a little bit more squeaky than others.
I have used several brand, the best so far is Mitsuboshi which is the same as you can buy from dealership.


Auto tensioner.

I also hear Gatorbacks are fantastic? But I am an OEM fan usually.

I'll have to try that 'water spritz test' to quiet the light squeal. Going to be plenty moist tomorrow after tonights rains so I'll try to get a startup video posted.
I almost wonder if the stationary idler pulley "rusts up" over night when humid and a has to "wear in" when first started after a 6-7 hour sit.

Water test is a good starting point. Also check the tensioner and pulleys for play.

Noise lessens/goes away = pulley misalignment.
Louder = tension issue
No change = bad bearing somewhere

Gatorback belts (now Continental) are good stuff. Their unique rib pattern makes them more tolerant of misaligned pulleys.

 

[MoreCowbellAz]

I went through this exact thing just last weekend except in a Kia Soul, would squeal when cold then taper off. It was the serpentine belt. I have to disclose that my circumstances were a bit different than yours in that I had just had the belt replaced and then it started squealing, but it was in fact the belt and not the idlers or anything. The squeal was exactly as you described.

 

[Rhymingmechanic]

My Silverado has been doing the same thing for a few years--light squeal for a short time on the first start during cold, damp weather. The squeal lasted a little longer recently, so I loosened the belt during a recent oil change.

The tensioner pulley bearing felt very rough, and the idler rough but less so. I can feel a little "catch" at one point when turning the alternator. The belt looks decent to be a 2001 part with 108,000 miles. Wear marks on the tensioner were within specs.

I got online to replace the belt and tensioner, and found a kit on Rockauto that also included the idler, for less money. I replaced all 3, and got rid of noises I didn't realize were there. Now, the next cold and wet morning should tell me whether the alternator caused the squeal.

 

[SumpChump]

Originally Posted By: MoreCowbellAz
I went through this exact thing just last weekend except in a Kia Soul, would squeal when cold then taper off. It was the serpentine belt. I have to disclose that my circumstances were a bit different than yours in that I had just had the belt replaced and then it started squealing, but it was in fact the belt and not the idlers or anything. The squeal was exactly as you described.


Thanks for posting! It means alot to know soneone else has experienced the battiness of these little squeals. LoL

 

[Rylan]

Originally Posted By: MoreCowbellAz
I went through this exact thing just last weekend except in a Kia Soul, would squeal when cold then taper off. It was the serpentine belt. I have to disclose that my circumstances were a bit different than yours in that I had just had the belt replaced and then it started squealing, but it was in fact the belt and not the idlers or anything. The squeal was exactly as you described.


In your case, was it a bad serpentine belt or misalignment?

Got the same 2.0L as the Kia with a similar light chirp at startup as the OP. It's been 25K miles since I did all the belts and pulleys.