Changed alternator, now I have belt issues!

[ericnord]

Hey everyone,

I changed my alternator yesterday, but now I'm having belt issues. First, my '99 X has a very brief 1-2 seconds of belt whine when you start her up.

Second, there is a constant whirring sound from the belt when the engine is running. It is hard to describe, but is is rhythmic, so it seems a particular part of the belt (brand new) is rubbing a particular piece every time it passes.

I ended up taking the tensioner all the way off during the install of the alternator, even though I didn't need to, so I'm wondering if the belt whine is because I tightened it back to tight. I'm not sure what the whirring is.

Any ideas!

-Eric

 

[CDW6212R]

Hello Eric, is it the SOHC? Check both idler pulleys. All of the pulley bearings are likely to go bad after 75-125k miles. You should check all of them any time the belt is off. Try to always buy the best belt. I got mine from Ford because it was no more than the best that Autozone had. The SOHC engines have had belt slippage issues. Ford would often install a 1/2" shorter belt. Good luck,
Don

 

[ericnord]

It is an SOHC. I don't think it is the pulley bearings, because it occured after I installed the alternator and I doubt it is a coincedence that the bearings should go bad the same 1hr it took to change the alternator.

Thanks for the input on the belt slippage issue.

-Eric

 

[CDW6212R]

I asked because I just went through the front of my SOHC. I bought all new chains, tensioners, hoses, idler pulleys, thermostat, alternator, water pump, power steering hose, and belt. I am now very familier with those front parts. Good luck,
Don

 

[ericnord]

Did you tighten the tensioner bolt as tight as you could, or back it off just a hair so it could wiggle at start up?

 

[Rhett]

Second, there is a constant whirring sound from the belt when the engine is running. It is hard to describe, but is is rhythmic, so it seems a particular part of the belt (brand new) is rubbing a particular piece every time it passes.

Long winded, heh. I am long winded..sorry about that:

I would open the hood with the engine off and inspect the belt all the way around its route. Look to see if it's hitting anything. If not, I'd start the truck and with the engine running see if it's hitting or rubbing on something.

Also, it could be that your tensioner is getting worn. Sometimes simply removing the tensioner and putting it back on is enough to finish off an old tensioner. Having said that, I put a new tensioner on my truck recently, and it's noisier than the old tensioner...

I have always made sure the tensioner is "pretty tight" attached to its bracket. I do not want it coming loose at any time. I believe last time I even put blue loctite on the bolt threads just in case. I do not know the torque spec on that bolt, but I imagine a Factory Service Manual would have it. A Haynes does not. I wouldn't make it loose though. The tensioner is designed to flex and pivot, to "give" a little.

 

[CDW6212R]

As I recall, the tensioner body is stationary on the other bracket(tight). The internal spring pivots the tensioner pulley freely. The pulley bolt should also be tight. Most of those front bolts are 5/16" to 3/8" in size, so their torque should be around 30-50lbs.ft.
(Bolt diameter determines torque needed).

Rhett, I have also changed a tensioner(93 Limited), and ended up with slightly more noise.

I have in the past changed one bad bearing part, as found, and usually ended up changing everything over time. On my 99 SOHC, while doing the valvetrain work, I have changed all hoses, and all bearing parts, except for the AC clutch bearing.

The whole tensioner from Ford was $45, but I only changed the pulley. I have some spare parts. Good luck,
Don