Belt squeal

[StreetRanger01]

The belt on my 2001 ranger 3.0 is making a whole lot of noise at idle and while driving. Replaced belt, idler pulley, tension pulley and the noise still goes on. It did stop for a couple days and came back. It isn't the alternator because we put a new one on and then took it off when the noise stayed. Water pump seems to be fine and same with the ac compressor. When I spray any pb blast on the belt or even water the squeal goes away for a few seconds then comes back. Any thoughts?

 

[SixFoFalcon]

What belt did you use? And did you replace the whole tensioner, or just the pulley?

 

[StreetRanger01]

Just used the cheap belt from autozone and I only replaced the tension pulley. Not the whole assembly.

 

[AircoolerKirk]

Man. Mine does that every single morning that its cold or damp. Guess I need to start with the belt. Is the tensioner normally bad? I don't think I've ever heard of that before.

 

[Bob Ayers]

The camshaft position sensor synchro also makes a squealing noise before it goes out. To check to see if this is what your problem is, remove your serpentine belt, and see if you still have the noise.

If the synchro goes toally out, you loose oil pressure, and possibly your engine.

 

[StreetRanger01]

started it up yesterday with no belt on and the squeal was gone. So it is something that the belt is running or the belt itself but it's new.

 

[SixFoFalcon]

FYI, it wouldn't be the first time I've heard of a "new" alternator being a POS right out of the box. I would be very wary of assuming that the alternator you tried was absolutely not the source of the noise. I know it's a long shot but keep it in the back of your mind.

I'm assuming that the tensioner is still applying decent tension to the belt? The only other thing that I can think of that you haven't eliminated would be the fan clutch or bearing, or the PS. With the engine off and belt off, try moving the pulleys by hand.

 

[Big Jim M]

I have had coolant pumps make a squeal for a short while before leaking coolant.. But never a fan clutch make noise... I've had em with extreme wobble but still quiet.
Big JIm

 

[fixizin]

Related, mentioned above, but not answered:

What's the test of whether tensioner is adequately tensionING?... e.g. torque wrench setting to drop it to the stop is...??

 

[Big Jim M]

Fixin The new type belts have such a grip on the pulleys I think the tensioner spring would have to be broken to allow enough slack to cause a slippage from lack of tension.
Big Jim

 

[thegoat4]

If you have a squeal that doesn't seem specific to any one pulley, but it's definately a belt squeal, you have a weak tensioner spring. Also, don't put PB blaster or any other lube on your belt. It WILL slip and WILL squeal. Spray the belt with some parts wash when running to take the oil off it. Or replace the belt and wash off the pulleys.

As far a testing the tensioner, if you're brave, put a wrench on it while running and see if manually applied tension will make the squeal stop. I've done it, but I do not consider it a good idea as one slip can send a wrench through your radiator or your face.

 

[fixizin]

Fixin The new type belts have such a grip on the pulleys I think the tensioner spring would have to be broken to allow enough slack to cause a slippage from lack of tension.
Big Jim

Not buyin' it Big... sure there's more rubber on the "road" than the old V-belts, but you still need some definite so-called "normal" (perpendicular) force of belt on pulley to turn over an A/C comp or water pump... what IS that number? (OTOH, FoMoCo should design that spring to be well within its elastic range, and a life-of-vehicle kind of part.)

Gotta get down and find my lost Haynes manual 'cause Chilton's on CD is worse than a blank CD-R... at least you can record something on the CD-R.

 

[289-tiger-]

PB blaster, pulleys, belt, squeal.
Lubricants like that are not designed for belts and will destroy them.
If you are checking a belt baby powder is a harmless alternative.(not designed for belts either)

Good luck

 

[Big Jim M]

fixizin Are you thinking them springs wear out? Losing strength? Enough to cause belt slipping..
Wow I wouldn't guess that could happen..
Big Jim

 

[fixizin]

fixizin Are you thinking them springs wear out? Losing strength? Enough to cause belt slipping..
Wow I wouldn't guess that could happen..
Big Jim

Sadly, with so many components and sub-assemblies made in ChiCom-land and Mejico, I have to keep even the possibility of beefy parts like spindles and axles breaking as "on the table".

Besides, what else explains general belt squeal, if your stethoscope tells you all the accessory bearings and idler bearings are good?

I still say somewhere, buried in an overpriced Helms shop manual, there's a torque-wrench test for the belt tensioner...