Belt squeal upon engine start

Just replaced all 3 belts and idler pully and now it’s squeals for a second upon cold starting. It Didn’t do this before. Is that normal or did I tension the belts too tight?

 

Belt is lose. I usually install belts, run the engine for a little while, and then recheck them. My reasoning is because they are stored in the little sleeve they are slightly misshapen so once you install them and run the engine for a bit they loosen up a little.

 

yep, belt is loose.

 

You could go the cheap and not actually fixed route in the meantime while wait on new belts..

A bit of a bar of soap.. CAREFULLY.. again.. CAREFULLY.. applied to the belts will stop the squealing for some time. Not a fix, but an audible bandaid until you can get it fixed.

Ps, little soap bar bits go everywhere

 

or just turn your radio up louder

 

Spoken like a true mechanic

 

I've got the same squeal. I checked the tension on all belts and the alternator has about 1 inch of give while rest are 1/2inch or less. I gotta get In there and tighten it. I just had the belts replaced as well.

 

this is much safer

 

Here's an inexpensive solution that I consider "accurate enough."

$24 Gates 91107 Krikit V-Belt Tension Gauge, Black

https://www.amazon.com/Gates-91107-...ator+belt+tension+gauge&qid=1592515378&sr=8-1

 

All belts come with an audible tension alarm.

If it's too loose, it squeals.

 

Interesting that you guys say it’s too loose cus if anything I thought they may be too tight. They all seem pretty tight to me is there a way I can judge?

 

This can also happen due to a failing fan clutch. I used to have the same squeal at startup, replacing my fan clutch I noticed it was nearly "locked-up" all the time. Meaning I could just barely move it twisting it with my wrist off the vehicle.

Might be worth going through the checks here in Tim's video or seeing if it takes excessive force to move yours.
https://www.youtube.com/watch?v=WzhlACxqeqQ

 

If it was tight enough to be so tight that it would squeal, that belt would sing like a guitar string if you plucked it.


If you really need a way to check, in machine maintenance (not neccesarily automotive) the standard is 1/4" of deflection over 1' of belt span length between pulley centers. .... it would be WAY easier for you to just go out and tighten all the belts tensioners.

 

Oh that's interesting man. I hadn't ever though of the fan clutch being locked up (failed) as a source for a quick squeal but thinking that through in my head, yeah it totally could. It's supposed to 'slip' at first until it heats up and locks up. Very cool
Thanks man, Learned something new

 

That sounds to be about the same rule of thumb for cars too. I'd say, after belt has been on and run for a few miles, about a 1/2" deflection at center between two pulleys ~ 1' run length.
It truly does become a feel thing, and logic would tell you its better to be a tad loose than a tad overtight.

 

The belt should twist no more than 90° between your fingers midway between pulleys. And it will feel too tight compared to most domestic V belts.
Grooved flat belts require more tension than V belts.