Screech on start up

[Mudstang9443]

When I start up my truck (happens with both remote start and key start) there is a very loud screeching coming from the belt I'm assuming. It only happens for a quick second and only on startup no matter if the engines hot or cold. I just replaced the belt a few months ago and it stopped for about a week then came back. Any one know what this could be? It's a 96 4.0L

 

[LONO100]

try making an adjustment to your alternator belt. sometimes when it gets cold, your belt can contract and get noisy when you first run your engine in the morning, and once it gets hot, it stretches out and the noise goes away.just a slight adjustment should cure the morning squeal. good luck!

 

[alohamonte]

screeching means slipping. so if you replaced the belt, the next step is the tensioner pulley. that pulley will keep the belt tight, so hot or cold, it shouldnt slip.

 

[swshawaii]

No belt adjustment. Remove the belt and check the tensioner.

Do NOT use belt dressing on serpentine belts whatever you do.

Signs of Belt Tensioner Failure
https://www.rockauto.com/catalog/moreinfo.php?pk=3674&cc=1119653

 

[rb142]

Probably the tensioner is worn out, or bottoming out if the belt is slightly too long.

 

[koda2000]

try making an adjustment to your alternator belt. sometimes when it gets cold, your belt can contract and get noisy when you first run your engine in the morning, and once it gets hot, it stretches out and the noise goes away.just a slight adjustment should cure the morning squeal. good luck!

Huh? No alternator belt and no adjustment for a serpentine belt. I suspect the belt tensioner is weak and allowing slippage. swhawaii is correct in that you should not use belt dressing on a serpentine belt.

 

[FordGT55]

Any chance its your cam synchronizer chirping? Take your belt off and start her up and if it stills makes noise there is a good change its coming from your cam synchro.

 

[2TimingTom]

Any change its your cam synchronizer chirping? Take your belt off and start her up and if it stills makes noise there is a good change its coming from your cam synchro.

Or on mine it was the starter making noise.

 

[Mudstang9443]

Update: I replaced the tensioner and it's all fixed no squealing anymore. Thanks for the help guys