Loud screeching sound (1 Viewer)

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Is coming from under the hood on the 55s 2F. It onlyhappens at higher RPMs in every gear. Sounds like it's coming from the belts area. So is it a pulley, and if so, what do I need to do about it?
This is the first it's happened and only after driving 5 hours at 60mph
 
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I'll bet you it's coming from the air injection pump - emissions part - belt driven. Unfortunately it shares the drivebelt with the water pump. There is a couple of different ways to approach this. Others will chime in shortly........
 
I would feed Louis some belt dressing to see if it helps. He sounds hungry and thirsty.

When Louis gets screechy, I just switch over to some vintage George Carlin for a while.
 
If not the belts or pully, it's could be the fan clutch locking up too soon and not unlocking when it should. Went thru this on my fj60, even though the FC was not very old, it was not working right, replaced and no more squelling.
 
The truck has been de-smogged and belts are new. I looked at the belts and they seem to fit fair tight.
 
well I would sure look at the FC, when locked(or staying locked up too long) up it puts alot a resistance on the crank pulley, which makes the belts squeal at a higher rpm in each gear

or, if its locking up, it may also be a overheating issues making the lock up like its suppose to to help cool

mine was doing it for more than a few years, just didn't make since it could be a OEM FC with 20K on it......but it sure was. $70 on amazon for a New Aisin, mileage went up at about 1 MPG and its alot more spunky now
 
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If not the belts or pully, it's could be the fan clutch locking up too soon and not unlocking when it should. Went thru this on my fj60, even though the FC was not very old, it was not working right, replaced and no more squelling.

The fan clutch is rebuildable. Different weight fluids are available. Our local club has done this enough with their 80 series to deal with the heat in the Southwest.
 
I have rebuild a few FC and was never happy with the results....always ended up with a new Aisin.

I suspect some issues with then are other tHan fluid...like the temp sensing spring or other voodoo
 
Take the belts off and see if the noise goes away. If it doesn't I have seen slingers come apart and cause all kinds of noise. If the noise goes away install one belt at a time to narrow it down. I have even seen where a person capped the valve cover air inlet and the Pcv sucked the seals dry and you could have sworn it had a seized bearing from the way it screeched.
 
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I'll bet you it's coming from the air injection pump - emissions part - belt driven. Unfortunately it shares the drivebelt with the water pump. There is a couple of different ways to approach this. Others will chime in shortly........
If that's the case, take the dang thing off and get a another v belt. Put it back on when / if you have to smog it.
 
The truck has been de-smogged and belts are new. I looked at the belts and they seem to fit fair tight.
If the belt(s) are not oem they will be slipping. Aftermarket are not nearly thick enough--they will go all the way to the bottom of the pulley, causing just what you describe.
 

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