Mechanics

CHEVY VAN FAN NOISE.

2003 Chevrolet Astro

Noises problem
2003 Chevy Astro 6 cyl All Wheel Drive Automatic 130000 miles

My astro van has started making a squeaking sound when fan is turning. I checked also when engine stop and turned fan by hand and it was squeaking. The van is not overheating just squeaking. I sprayed some WD-40 around fan and it still squeaked. What could be problem and should I be worried.
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Larrod30
October 18, 2009.



The bearing are probably going bad. Check to see if there is any play by rocking the fan blade back and forth (perpendicular to the shaft).
There may not be play yet. Try to narrow down if it is coming from the motor and not rubbing on it's cowl.

I tried to move fan and it would move left, right, back or forth no movement. It started yesterday and its not a constant sound.

Tiny
Larrod30
Oct 19, 2009.
Fan Clutch may be fine then. This may be a belt noise. Look at the belt for cracking or glazing. IF there is cracking replace it.

If you put some valve grinding compound on the belt, both sides of it at various points while the engine is off, then start it, it may remove any glasing and noise.

It only makes a squeak like sound when I turn the fan about 1/4 turn each time it turns. The belt is pretty new and looks fine. Not overheating just alittle worried because I have to make a 9 hour drive to get home from where I am. I should also say I am in cold weather in Michigan.

Tiny
Larrod30
Oct 19, 2009.
Well, if it was mine I would remove the belt and turn the fan to determine if the squeak remains or not.
First it eliminates the belt, second you can spin the fan independently of the other pullies it is tied in with. IF the squeak remains, then you have to decide if you want to change the waterpump more than likley. The bearings may be going bad in the pump. Since there is no movement in the shaft,it would be an early indication of things to come. Meanwhile other pullies can be spun and felt for roughness, play or noise.


http://www.2carpros.com/forum/automotive_pictures/30961_ast_1.jpg



However a stethescope can be also used to possibly pinpoint the squeak if it is consistent enough without removing the belt.

Even though the belt is new I would not eliminate it as the source. A quick test is to spray -(very lightly) something such as wd-40 on the belt while it is moving a quick blast on the inside and then on the outside of the belt. (Careful as too much spray can cause the belt to come off.) If the noise stops, it is the belt. Close the hood and forget about it. But the source needs to get nailed down if it isn't.