Mechanics

SCREECHING WHEN STARTING

2002 Isuzu Bighorn • 200,000 miles

There is a loud squeel coming from the engine when I start cold. It's not there at idle speed but when I increase the revs it appears. When the engine has warmed up the problem goes away and I can drive with no problem. Until the next time I turn off the engine and then try to start again.

I thought it was a belt slipping but had them tightened and the problem remains.

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Does it have serpentine belt? Those can be tightened without it helping. Also regular belts worn dont help to tighten. Sounds like alternator pulley is squealing by your symptoms. Check it out under hood.

Tiny
Fixitmr
Jan 25, 2012.
Thank you The belts are brand new and I took the vehicle back to the workshop to have them tightened. They are now much tighter (I don't know what a serpentine belt is).

So excluding belts it sounds like I need to concentrate on the alternator as you suggest? Perhaps a bearing on the alternator pully?

Serpentine belt is a wide flat belt vs standard narrower V shaped belt. If you have hood open during offending expected event you may be able to identify source especially if aided by listening device.

Tiny
Fixitmr
Jan 26, 2012.
OK that's what it is. A flat belt with rubber serrations on the bottom side - not a V Belt. I have listed but the screech is so loud it fulls the whole engine compartment. It puzzles me that is goes away after idling for 5 minutes - its as if something has warmed up and then goes fine. Would the belt itself squeel until warm? Or would an alternator pully or bearing squeel until warm?

The self tensioner may be loosing tension or there may be a contaminate on the belt.

Mhpautos
Jan 28, 2012.
Alternator has more drag after starting until battery is brought back up to specs.

Tiny
Fixitmr
Jan 28, 2012.