What could be squeaking?

[nutt7]

I have a serpentine driven 350 TBI. I have an annoying squeak, not a constant squeal, but a repetitive, rotational squeak-squeak-squeak. It does it at lower RPMs, although I just might not be able to hear it over the engine at high RPMs. When I turn off the engine it lets out a last "squeeeee".

It sounds like it's coming from the balancer or the water pump pulley. The shaft that goes to the fan spins perfectly, but the water pump pulley has about 2mm side to side movement when running. The harmonic balancer spins perfectly.

I thought it was the A/C idler, (well it was squeaky too), so I replaced it, but something else is still squeaking. My belt is about 5 to 6 years old with probably 30k miles. Any ideas before I throw money and parts at it?

Thanks

 

[woodwright]

My suburban is doing this too. Pretty sure its the Tensioner.

 

[nutt7]

You mean it losing its tension, or the pulley is bad? Do you know how to verify if the tensioner is bad? belt deflection?

 

[Deuling]

Does it squeek all the time? With electrical stuff off/on? Alternators can be a big source of da squeekies sometimes.

 

[woodwright]

You mean it losing its tension, or the pulley is bad? Do you know how to verify if the tensioner is bad? belt deflection?

Not really sure. Mine only squeaks when its warm, and doesn't squeal under load. I had the belt off the other day, and when you spin the tensioner by hand it squeaks a little, but doesn't seam to have any play. Its my beater work truck so I don't really care as long as it starts and goes.

 

[Burbdood 74]

Another vote for the tensioner.

And it's not likely to lose tension on the belt, but it could sieze up and burn or snap the belt when the bearings inside burn up.


IIRC, the recommended practice of servicing the belt is to throw a new tensioner on every xxxxx miles, (can't really remember how many miles exactly).

 

[nutt7]

Does it squeek all the time? With electrical stuff off/on? Alternators can be a big source of da squeekies sometimes.

The alternator squeaks when I turn it by hand, but its silent when running.

Another vote for the tensioner.

And it's not likely to lose tension on the belt, but it could sieze up and burn or snap the belt when the bearings inside burn up.


IIRC, the recommended practice of servicing the belt is to throw a new tensioner on every xxxxx miles, (can't really remember how many miles exactly).

When I had the belt off, the tensioner pulley turned fine with no noise or resistance...the noise is around the water pump pulley or harmonic balancer.

 

[woodwright]

Check your water pump. The hub is just press fit on to the shaft. A few weeks ago mine came off and the fan, pulley, and hub came off at speed and ate my radiator. But after I swapped the water pump, the squeal was still there. I still think its the tensioner.

 

[Burbdood 74]

Start the engine and grab a long screwdriver and put one end on the accessory you think is squealing and put your ear on the handle. The screwdriver will act like a stethoscope and you'll be able to pinpoint what's squealing.

 

[496truck]

And a good way to see if it's the belt...

While it's running, spray some water on it. Don't soak it, just a bit from a spray bottle. If the noise stops or gets worse, it's the belt. Replace with a high quality belt, like a Goodyear belt.

I went through this with an S10. Replaced the belt 3 times (parts store brand), tensioner twice, new idler. Looked online for similar problems, someone said to replace with a good belt. Put a goodyear belt on it and the squeak was gone.

 

[nutt7]

Thanks, I'll try that. The screwdriver thing was a bit sketchy with the fan and all...I didn't want to get too close and become the next Phineas Gage

 

[Burbdood 74]

Thanks, I'll try that. The screwdriver thing was a bit sketchy with the fan and all...I didn't want to get too close and become the next Phineas Gage

Well obviously you go from the side of the engine....

I've used this method for awhile, it works good and I can be....."coordinationly challenged" from time to time. And I still have all eight fingers, my left ear and the scar on my cheek is barely noticeable from 50'.