engine and drivetrain Squealing From Motor

[paulram]

I cut the belt on my air pump today (removing it as soon as I can fit in the garage). I assumed the squeal I heard when giving it gas would be gone.  It is not.  I checked the alternator belt and it is snug.  What else could cause that whining?  I don't hear it when I gas the motor by hand at the carb, only when the motor starts pulling (2500 RPM +).  It definitely sounds like a squeaky belt.

 

Thanks.

 

Paul

[Buckeye]

How old & condition of that belt?

Take the belt temporarily off and try to rev the engine. Do you hear the noise?

Try with new belt again. If squeal sound persist, then I would think suspect is water pimp, alternator or even worn out water pimp pulley

[Simeon]

Try spraying some WD40 on the belt and pulleys. If that stops the squealing (temporarily) then it is your belt.

Check the belt is running in the correct v on each pulley and is aligned on the same plane.

[Cyclone101]

water pimp pulley

I've been called many things... But this is a first!

[jrhone]

Is it a squeal or high pitched whine? My car had a high pitched whine that got REALLY loud. I thought the engine was going bad it was so loud. It surfaced after a 800 mile road trip so I thought I pushed it too hard. Checked oil pressure with a gauge. All fluids. All gauges were normal and power was normal. Sprayed carb cleaner all over the place and still no change. Finally found it when a rag was placed near the carb and the sound muffled. It was the throttle shaft on the carb letting in air and "whistling" loudly. May not be the sound but if you can't find a bad belt then try that.

[jrhone]

Sorry for the double post

Edited July 18, 2013 by jrhone

[paulram]

I cut the second belt to the air pump as it was loose and worn.  I had already replaced the alternator/fan belt with a brand new belt and it is tight.  I can spray the belt to see if it goes away.  If not is it best practice to just replace the water pump anyway?  Is there any way to diagnose high pitched squealing in an alternator or water pump?

 

Again, I don't hear it when i throttle the car by hand, only driving.  Maybe it is something else.

 

Paul

[justinevert]

If it is not the belt, check the alternator bushings, they tend to wear out over time and make a tremendous racket! There are urethane version that are much better than stock.

[Honolulu]

I would not touch the water pump without good reason.  Frequently the bolts holding it on are rusted very tightly to the block, and snap when you try to remove them.

 

Now, a good reason would exist if the pump were leaking.  To check, get your head under the car, preferably with engine warm and idling, hand brake set, and look up at the underside of the water pump.  There is a hole under the pump body leading forward to the fan, a scant 1/8 inch in diameter.  If there is coolant dripping from the hole, your pump is well on its way to hell.  If there is a drop of water, it's still coolant, and your pump is telling you to program a pump R&R.  Pumps are about, what, $45, and should be readily available from all the usual suspects.

 

As stated above, the work is in carefully removing the bolts without snapping one or more.  I get a 6mm tap and clean the hole threads, run the bolts on the wire wheel if I don't replace them, and use plenty antisieze in the holes so the next time (yes there will be a next time) the bolts will come out without snapping.

 

The other possibility for squealing is that although the alternator belt feels tight, we don't know what your definition of "tight" is.  2002s like to use engine compartment heat to slowly degrade the alternator mounting bushings, then the alternator is slightly but visibly out of alignment with the other pulleys and the belt will squeal although it feels tight.  You have to look at the alternator and other pulleys carefully and assess whether they are in alignment.  If not, "all the usual suspects" will sell you urethane alternator bushings which are supposed to never degrade.  Many 02s have these already, they are commonly red in color vs the black rubber originals.  Other colors could occur.

Edited July 18, 2013 by Honolulu

[echrisman]

Sorry to revive an old topic, but I just went through a really similar issue and finally have some resolution. After reading jrhone's post above, I was able to track the sound down to my carb (I had already spent a week going through my belt, alternator, distributor, etc. etc...)

 

Turns out in my case, the entire carb was loose, just floating on the gasket where it mounts to the manifold! *d'oh*. Previous owner either didn't torque it down when it was installed, or it worked its way loose, but I could easily move the entire thing side to side. It was making a terrible cyclic squealing sound as it sucked air through the gap. I tightened the mounting bolts and viola! No more noise.

 

Something very simple to check and very simple to fix, before you start digging into waterpumps, etc... FYI for future squeal hunters!

Edited August 21, 2014 by echrisman