NGC Serpentine Belt Area Squeal...Mechanics question?????

[bobrebos]

On my 1990 Ford F150, 5.0 V8 with Air Conditioning, I am getting a squeal from the Serpentine belt area.

I sprayed the belt with water and the squeal immediately goes away for a few seconds.  According to my knowledge and others that would indicate a belt alignment problem. 

I checked the pulley alignments and they seemed to be allligned.

Could it be a bad belt tensioner?  But if water stops the squeal that would tell me it is an alignment issue.....  Previous owner replaced the belt within the last year.

Would you replace the tensioner next or?  I listened to the pulleys with a long screwdriver trick and couldnt hear any squeal coming from any pulley.
Im running out of ideas here......I think Il re-check all the pulley alignments again.  Any great tricks or ideas???????

[guzzisteve]

Good idea, the PO may have left a spacer out if he took the stuff loose.

[pat80flh]

The automatic belt tensioner is spring loaded, and the spring can get weak over time. 

My test for a weak tensioner is to CAREFULLY get a wrench on the tensioner(with engine running) and increase the tension/tighten the belt.  If the noise diminishes/goes away, the tensioner is weak. If not, you may have an alignment problem, but that is very rare. And a new belt may temporarily solve an alignment problem, then come back.

  Serpentine belts are very touchy, and I replace belt and tensioner as a pair.

[Two Checks]

Just replaced the water pump on the 92 Dakota.
I removed the tension on the belt and removed the belt. Removed the wrench from the tensioner and it didnt spring back. Replaced the tensioner and now the power steering doesnt get grabby in parking lots. And you can watch the tensioner move while the engine is running.
I would replace the tensioner/pulley assy and belt. A loose tensioner can cause the belt to slip and form a glaze.

[nick949]

2005 Buick Allure (LaCrosse). I had a ghastly squealing from the belt which would go away for a while if I bathed it in belt dressing.  However, it wasn't the belt at all - it was the water pump. Had the water pump replaced - all squealing gone.  Don't jump to any conclusions and check everything carefully.

Nick

[bobrebos]

So I could not find any pulleys that were out of alignment so I checked the tensioner pulley, and it seemed to lighten up a bit as far as squeal noise goes when i applied more tension/pressure via the wrench while it was running.  (Keep your fingers out of the way!!!)

But the noise was still there (Squealing)  Water Pump was replaced within last year so I was pretty sure sound was not coming from there.

So I purchased a new belt and a new tensioner pulley.  I put the pulley on first with the old belt.  Seemed like noise was the same or maybe even worse.  So then I put on the new belt.  Squealing is gone.  Running nice and quiet.

Now I shall see how long this lasts......
 

[pat80flh]

Did you replace just the tensioner pulley or the complete tensioner assembly?

[bobrebos]

Did you replace just the tensioner pulley or the complete tensioner assembly?

I replaced the complete tensioner assembly. 

[Chesterfield]

Usually a spray with silicone quiets squeaky belts quite well. It let`s you know if it`s the belt or something else squealing also

[Triple Jim]

Usually a spray with silicone quiets squeaky belts quite well. It let`s you know if it`s the belt or something else squealing also

I would think that oiling a belt would tend to make it slip quietly.