Last weekend I replaced the aging, cracking serpentine belt on my girlfriend's '93 850 auto. This morning as she was leaving for work, I noticed that were were two new sounds that seemed to be coming from the belt/accessories area:

1) A periodic squeak that I assume was related to starting it in the relatively cold morning.
2) A sort of rumbling/vibration that sounded like it would've been caused by components vibrating at low to medium speed .. possibly the power steering pump assembly (but maybe not).

I will talk to her sometime during the day and find out it they (in particular the squeaking) went away after the car warmed up.

Didn't expect to have this kind of problem with a new belt Could the new belt's tightness be causing this? Does that indicate I need to get a new tensioner?

Tomorrow morning I will loosen the belt and see if I can get any squeaks from manually turning the tensioner pulley and the idler. I just wanted to check up on it here to see if anyone had any insights first.

 

Usually that is a weak tensioner that jumps and makes the noise you hear.

 

I should've noted in my first post that a while ago I did post about the tensioner making a ticking sound as it vibrates back and forth. The new sound is more of a rumbling (lower frequency than the tensioner vibration).

But perhaps the weak tensioner is causing other vibrations?

Edit: to clarify, the tensioner ticking has NOT changed into a rumbling. The rumbling is new and it sounds like the belt is causing bulkier stuff to vibrate, like perhaps the power steering pump.

 

Maybe but they are now known to go bad.

 

OK. I'm going to check in the morning to see if the tensioner or idler pulleys squeak when turned manually just in case, but it sounds like I'll probably need to get a new tensioner. Looking on FCP Groton, the tensioner is easy to identify, but they also list a "tensioner roller". From the picture of the tensioner they provide it looks like the pulley is included. Is the "tensioner roller" just the pulley in case for some reason you need it but don't need the tensioner?

And one final question on this, where can I get the torque specs to use to mount the tensioner? I've got the Chilton manual for the car and as far as I can tell that thing's useless as far as torque specs go..

 

Yes thats what it sounds like they sell the pulley only if you need it.
But it is usually the tensioner that is weak.

Not to sure about the torque spec.
I just tighten the bolts till I feel comfortable.

 

If the belt you took off was so old that it was cracked and deteriorated, I am willing to bet that the tensioner (and pulley) and quite possibly the idler pully are in need of replacement as well and are most likely causing the noise. Call me one to over do it, but when I change belts, I usually change all associated parts as long as I am in there. As for the squeak, my new belt squeaked for about a week each first start of the morning for about a week after installing. Most likely it needed to get seated in as the squeak only lasted for about 10 seconds eact time.

Just my .02

Glenn

 

Psaboic: The old belt was not in terrible condition. Some cracking on the tooth side but it wasn't really degraded or anything, I don't think it would have screwed up the pulleys, but I guess it's possible. What kind of damage are you talking about, surface damage or warping the rollers out of round?

Given that my tensioner is already noisy, I'll probably just replace it and see if the noise goes away. If not, I'll go for the idler pulley.

 

>I just tighten the bolts till I feel comfortable.
I hope one isn't as muscular as the governor in California (or is it now officially pronounced "Kalifornya?").

Did you install the OEM belt? The Continental Tech OEM belt is noticeably different, especially on the back side; they come with criss-cross patterns for better "bite". If you did use this OEM belt, then one of the pulleys may be shot.


JPN

 

Most likely the belt did not damage the pulleys. Only damage I have ever seen to old pulleys is worn out bearings. Most times you can simply change the belt, and if the tensioner is good, then everything will be just fine. I change all the pulleys and tensioners every other belt change just to be safe, but that is me. I'll be willing to bet there are many 850's with well over 150K still running with there original belts tensioners and pulleys.

 

Just wanted to close out this issue. I replaced my tensioner today and both the tensioner clicking and the rumbling sound are gone.

For posterity and future searches:
I used a deep socket and a craftsman thin profile ratchet (with a u-joint extension for part of the job). The job would've been a lot easier with either a deep socket about 75% the length of a standard deep socket (don't know if these exist) or with a deep socket with a hex pattern on the end so you can slip a ratcheting end wrench on instead of using a normal ratchet.

Thanks for the help!

 

Glad you got it fixed.

 

Well done.

Snap-on makes semi-deep sockets, which may have been helpful. Or, next time you could buy a cheap socket and grind it down.


JPN

 

Glad we could help...

Glenn