Why is my '93 GMC Sierra squealing?

[Lode Vaduh]

Upon cold startup, there's no noise. But after a few minutes once the engine has warmed up, there's this ear-piercing high pitched, continuous (not to rhythmic) sqeualiing coming from the engine.

Here's what we've replaced:

Belt (including a special, anti-sqeuak belt)
Alternator
Water Pump
Tensioner Pulley

And this squeaking DOESN'T happen when the wheel is turned, so we've inferred that the power steering pump is alright.

The sound seemed to be coming from the driver side of the engine compartment, where the alternator and power steering pump are.

But now we took the carburetor "dome" off, and it almost sounds like this horrid noise is actually coming from the injectors...Are we nuts?

Thanks!

 

[bobweb]

It's better to let any trusted mechanic you know listen to the sound and he'll most likely know what it is compared to guesses you'll get here if it's not a squeaking belt problem. Find professional technicians in your neighborhood here: http://www.IATN/shopfinder

 

[Molson02536]

Upon cold startup, there's no noise. But after a few minutes once the engine has warmed up, there's this ear-piercing high pitched, continuous (not to rhythmic) sqeualiing coming from the engine.

Here's what we've replaced:

Belt (including a special, anti-sqeuak belt)
Alternator
Water Pump
Tensioner Pulley

And this squeaking DOESN'T happen when the wheel is turned, so we've inferred that the power steering pump is alright.

The sound seemed to be coming from the driver side of the engine compartment, where the alternator and power steering pump are.

But now we took the carburetor "dome" off, and it almost sounds like this horrid noise is actually coming from the injectors...Are we nuts?

Thanks!

Have you inspected and idler pulley, common for the bearing to go bad and only makes the noise when it warms up.

Here is a link to the accessory pulley to your engine and number 8 is the pulley that may have the bad bearing or the A/C compressor bearing my have gone bad.

Good luck and keep me posted, you can try spraying WD-40 on your A/C compressor clutch to see if the noise goes away. If it does, then the bearing has gone bad and the A/C bearing and clutch will need to be replaced.

http://www.compnine.com/index.php?u...delid=6896&capuid=1&majorgroup=01&grouptype=B