Intermittent chirping sound in engine compartment

[ratterrier]

Hi...and thanks for looking into this topic.

My '96 Explorer has been making fairly loud chirping noises that sometimes last for about 10 minutes, sometimes 1 minute, and sometimes doesn't happen at all. The only alteration that I did before the sound became noticeable was to replace the serpentine belt with a smaller one that avoids the AC compressor (which locked up). Advice from others at that time was that doing this wouldn't be a problem...and a good quality belt was available for a truck without AC.

The chirping did not start for well over a month after this install, and the belt was actually real quiet. But I'm wondering if maybe I stressed out the tensioner by stretching the belt onto it. However, it is very tough to pinpoint where the sound is coming from...even with a mechanics scope. Is replacing a tensioner a reasonable attempt, and are there any similar situations or installation pitfalls that anyone may have experience with ?

Thanks,
Rat

 

[falls guy]

Probably the bearing in the tensioner pulley. Try spraying a little WD40 on the tensioner pully bearing(center) without getting any on the belt. That should tell you if thats it. Or maybe the belt has streched or wore a bit and is too loose. Try fitting the next size smaller belt on if that's the case. Good luck.
Peace

 

[ExplorerDMB]

what kind of belt is it? I have seen and heard a lot of new NAPA belts that have gone bad after a few months

-Drew

 

[aldive]

The sound you describe could definitely be one of both of the following items going bad: belt tensioner and idler pulley.

Good luck .....

 

[Rhett]

On my truck it the bird chirp was the idler pulley. the bearing was worn out.
Lasted 10 years and 100,000+ miles though.

One way to check the idler pulley is to remove it. (You will, of course, have to remove the belt to do that.) Once removed, if you hear much bearing noise when turning the pulley, then it's probably the cause. It should be pretty quiet if it's a good pulley.

 

[ratterrier]

Thanks for the replies. To answer ExplorerDMB, I believe it was called a Gator belt. It was much more substantial than the other belts offered. I'll try to look into the idler pulley as well, one problem is the chirping is sometimes nonexistent for days.

 

[aldive]

one problem is the chirping is sometimes nonexistent for days.

When I replaced my idler pulley and belt tensioner, the problem that necessitated the repair was an intermittent noise just as you described.

When replaced, the noise vanished.

 

[Rhett]

My idler pulley would only chirp in cooler weather, such as first thing in the morning.

And I think that's a Goodyear Gatorback belt you're talking about...