Something up front is squeaking like a mother on my 97 truck and its driving nuts.

I found a bad bearing on the grooved idler pulley so I replaced it and the sqeak persists. The tensioner pulley bearing seamed like it might be a little worn so I replaced it, but to no avail. Once I had the old one off, I concluded there was nothing wrong with it.

Is it interchangable with the smooth idler pulley? The one thats on it appears to be somewhat new, but maybe I should replace it just to be sure. I doesn't feel like anything is wrong with it though.

The water pump is newer. The vacuum pump is newer. (PO replaced them). The PS pump and alternator appears to have been replaced at some point too. The squeak doesn't change when the A/C compressor is engaged or not.

Tomorrow I'll try a new smooth idler pulley, but I doubt it will make a difference. Its terribly frustrating.

Has anyone else experienced this?

 

I hate to say it but even though your vacuum pump is newer, that's what it sounds like to me. They have a sealed bearing inside that squeaks when they start going out. My pump worked fine, but I replaced it to get rid of the squeak. I keep it in the toolbox as a emergency spare.

I could isolate it and make it stop for a few seconds by spraying WD40 on the shaft behind the pulley.

 

That makes sense. Last summer the pump pulley cracked. Everyone said that meant it was siezed up, but I could turn it by hand, so I just replaced the pulley. Maybe the bearing grabbed for a second causing the pulley to break. It was about that time that the squeak started, but it has steadily gotten worse.

 

Wow, I'm surprised it hasn't broken another pulley. They are made with pretty cheap bearings. I'm sure that's whats squeaking if you have already replaced a broken pulley. At least they are not too hard to replace, just kinda spendy if I remember right.

 

Phil, I just went through this with my truck. I sprayed WD40 on all the pulleys and the squeak would stop for a second, then it was right back. I changed the belt, and no more squeak. Try a new or different belt.

 

Get a auto stethoscope and check sll the pully bearings

 

I got a mechanics stethoscope, but couldn't find the squeak I was hearing. So I swapped the belt from my 96 into the 97 and the squeak was gone. I put the squeaky belt onto the 96 to see if it squeaked on that truck too, but it didn't (at least not yet.)

The non-squeaky belt is a Motorcraft belt, but the squeaky belt is aftermarket. I can't remember what brand right now. Comparing the two side-by-side I could see several differences.

 

The squeak seems to be slowly returning! Is it possible that I need to switch to the dual tensioner?

 

I had that problem too and like everyone else has said, that pump tho newer is what it sounds like the problem is

 

It doesn't sound bad with the stethoscope though...
And how do you explain the noise going away temporarily when I changed the belt if you think its the vacuum pump?

 

I honestly cant explain it but that's what mine did when I put the old belt back on, it stopped but it slowly started returning until I replaced the pump, either way hopefully you figured out what is causing it that squeak is extremely annoying!

 

Phil, my theory is when you replaced your belt its not stretched as much as the old one was so the tensioner would most likely exert more force on the belt until it stretches over time. This in turn puts more pressure on all the other pulleys and accessories including your vacuum pump. A change in the pressure on the pulley and bearings could make it stop for a while and start coming back as the belt stretches.

With everything you've tried already and the previous issue with that vacuum pump, I still think that is the squeak.

 

I found the AC clutch to be a problem on one of my trucks. It eventually seized and broke the v groove part free from everything else. It slowly ate through every thing on the front of the pump.

 

With the squeak back, I decided to re-visit this thread.

I haven't had any trouble with the vacuum pump since that broken pulley. Using the stethoscope it sounds just like the one on my 96 so I don't think that is the problem.

I notice a little in/out shaft play in the power steering pump, and upon closer inspection it looks like the pulley is out of alignment with the rest of the pulleys. It is about 1/16" too far to the rear. This is causing the belt to slightly ride the back edge of the water pump pulley. As the belt travels around the water pump it slides forward to the center of the water pump pulley. My current theory is that this sliding is the squeak that I hear.

So how much in/out shaft play is acceptable on the PS pump? If the PS pump is ok, can I just use a pulley puller to move the pulley out 1/16"?