squealing

[delsilver]

When I started my truck (93 W250 auto AC) there was a squeal coming from the engine. Sounded like a water pump so I pulled the serpentine belt and checked puleys AC, tensioner, fan, alternator and water pump. the water pump seemed to have a rough spot so I changed it out.
Not the problem, still have the squeal.
this leaves me with 2 options either the power steering or the turbo.
When I shut the engine off the squeal does not die instantly but tapers off. I am leaning towards the turbo, any thoughts.
I will get a stethoscope from one of the mechanics where I work and see if I can narrow it down.
Any help greatly appreciated

[dazedandconfused]

Pull your intake off and check the turbo for play. You can spin it and see if it makes any funny noises.

[delsilver]

dazedandconfused, I will check that out, should have thought of it myself.

[dazedandconfused]

Sometimes we all over look the little things.

[delsilver]

Took the intake hose off and there is no end play and minimal if any sideplay on the inlet end.
Will pull the serpentine belt off again and run without for minimal time check for squeal without.

[1STGENFARMBOY]

If it is your turbo something may be going on with the oil supply line,

but your gonna narrow it way down by running it with the belt off.

I have also heard some pretty freeky sounds with a vacume (break booster gromet) or preshure leak
(preshure tubs or intercooler).

Dar

[delsilver]

Thanks for all the sugestions, turned out to be the simplest solution removed the serpentine belt and no squeal. Word of advice, don't use belt dressing. Took me 1/2 an hour to clean the residue off the pulleys etc scrubbing with laquer thinner then wiping that off with methyl hydrate before putting the new belt on.
I now have a new water pump with what is probably a perfectly good spare needing only a new o-ring to reuse.
What i thought was a tight spot on the water pump must have been residue from teh belt dressing as well because it now spins freely with no play.
Moral of the story fix the simple stuff first.

[1STGENFARMBOY]

Well thats about the best thing it could have been

Dar

[Mike337]

Just an old quick fix for this..with the truck off put a little Comet or Ajax (house hold powdered cleaner) on the belt, Start the truck (make sure no ones face is in the engine compartment) the excess will blow off. Beats belt dressing.

[bmoeller]

If the noise comes back, The spring in the tensioner might be getting weak.

Mine was good and strong, but was causing the belt to run off the side of the pulley some. New tensioner and new belt, all is well.