Tensioner Pulley Squeal

Discussion in 'SN95 4.6L Mustang Tech' started by sneaky98gt, Jun 10, 2009.

  1. So I have a really loud and obnoxious squeal coming from my car. It will go away after about 10 or so minutes between idle and 2500 rpm, but before 10 minutes, or after 2500 rpm, it's really loud, and I'm getting really annoyed by it. I'm about 99% positive that it is the tensioner pulley because when I sprayed it with some Free-All, it quietened down right away, but the squeal came back about 5 minutes later.

    I think the bearing is about out on the pulley. I can wiggle it somewhat easily. It definitely has some play, but I'm not sure on exactly how much it should have. Should it have a little motion, or is it supposed to be completely solid?

    Ok, so no big deal, right? I'll just put a new bearing on. Here's the problem. I noticed the serpentine belt on the tensioner pulley was running off slightly on the back side of the pulley. Only about 1/4 of an inch, but it isn't running straight on the pulley. My concern is whether or not the bad bearing is what is causing this, or if the new set of underdrive pulleys that I just installed has something to do with it. I'm probably gonna replace the bearing anyway, but I don't want to still have the belt running off the back of it, as I don't really see the belt lasting like that. Has anyone had this problem before or what? Any advice is greatly appreciated. Thanks.


    Oh yea, almost forgot. My PI cam bolts are now in. Cams will be going in this weekend. :banana:
  2. Mine does the same thing but it squeals all the time, sounds like a centrifical blower. Im just gonna replace the pulley and bearings. Mine has been like that since I got the car, dont think you should be to concerned
  3. You don't just replace the bearing as far as I know. You replace the pulley itself which comes with the bearing built in. Not the whole tensioner assembly, just the pulley.

    Also, look at the pulley from the side of the engine and make sure it still lines up perfectly with the other pulleys. This is what could be causing the belt to ride wrong on the pulley. If it doesn't line up right then the tensioner itself is wearing out and the whole assembly would need to be replaced.

  4. Hey,

    I had the same problem
    I changed the pulley but still squeaked turned out to be the serpentine belt.:nice:
  5. The bearing is not serviceable in those idler pullies. Just get a new one. If you feel any play in the pulley it needs to be replaced.

    You may also want to check the tensioner while your at it. Mine bit the dust recently. The pulley was bad and also the tensioner had lost its ability to hold the correct amount of tension. I could tell because it would bounce around with the engine running.
  6. I'm probably gonna go ahead and replace both the tensioner and idler pulley. Both have some motion in them, and I'm already gonna be working on the car this weekend anyway. I'll also probably go ahead and replace the belt while I'm at it. It hasn't been replaced in the 3 years I've had it, so I'll go ahead and do it as well. So no big deal here.

    However, regardless of what is causing the squeak, I'm still a little worried about why the belt is running off the back of the pulley. I guess the tensioner could be bad, but I don't really think it is; it still has plenty of tension. How do I check for sure if it is ok? As I already asked, will the new pulley/bearing fix that problem? Or is it most likely the tensioner being bad? While I really hope it isn't, could the underdrive pulleys be messing up the alignment? I don't think they are, but I really don't know how to tell. Thanks for all the help so far guys.

  7. ....as for the belt not lining up with the pulley(s),and seeing that you stated that you installed new underdrive pulleys aswell,i was wondering if you got the right underdrives for your year model?There is two different water pump styles,long,and short.So there is two different p#'s for the underdrives that are year to year specific.Just a thought.:shrug:

  8. Yea, they are the right year model. And if I remember right, the water pump pulley isn't next to the tensioner pulley, but because I don't feel like going out to check at this hour, I can't say for sure. The crankshaft pulley and the A/C pulley are the ones before and after the tensioner, if I remember correctly.

  9. Just checking,cause it could be possible,you never know!:shrug:
    And the tensioner is beside the water pump.;)
  10. Apparently, the belts don't run the same way in my car as your car. My tensioner actually is between the AC and crankshaft. Mustangworld University Scroll down about 3/4 the way down and it has a diagram of how my belt runs.

    Does anyone know it would be the bad bearing, bad tensioner, or u/d pulleys causing the belt to run off the back of the tensioner pulley? I'll try and get some pics up as soon as I can.

  11. I had the same problem a while back, just bought a GATORBACK belt and have not had one single peep from the engine since.
  12. I don't know which one exactly fixed the problem, but a new tensioner pulley, idler pulley, and S belt fixed the problem. :)

    And now for the big day tomorrow....PI cams going in. This is probably gonna be an adventure, but I can't wait to get it done. :banana: