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'97 Taurus GL 3.0L 163k: Pinpointing Pulley/Belt Squeal/Chirp

'97 Taurus GL 3.0L 163k: Pinpointing Pulley/Belt Squeal/Chirp

Almost a year to the day I replaced the bearing on my idler pulley (along with the serpentine belt because it had gotten burned up when the bearing seized), I’ve got a squeal/chirp noise again. It’s most audible at idle up to about 40-something mph. Above that you can’t hear it. I tried listening at idle to see if I could pinpoint the source, but I couldn’t. Is there a way to do this? Should I try spraying each pulley with lubricant one by one until the noise subsides? It’d be nice if I could systematically re-arrange the Serpentine Belt to take one pulley out of the loop at a time. That would certainly work.

The concern I have right now is if it’s a bearing again (idler pulley or alternator, etc.), it could seize up and destroy my newish belt again (and I’d be stranded somewhere, right?). Of course, the other question is if it IS the idler bearing again, why did it fail after only one year???

Check to make sure the chirping noise is not coming from the drivers side of the engine under the intake manifold. If it is coming from there then its probably the
CMP Synchronizer that going bad. If the synchronizer fails completely it will stop the oil pump because the pump is driven off the Syncronizer. Also only replace with a OEM Motorcraft part.

With a long screwdriver, you can place on different components such as the alternator, A/C compressor with the handle on you ear and you can get a good idea if the sound is comming from that are of the engine. Use caution that you don’t touch the pulleys or the belt.

You can spray water (use a squirt bottle) (immediately behind) each pulley in turn to try and eliminate the squeal or remove the belt and turn each pulley by hand while applying some side pressure and listening for scraping or scratching noises.

Use the water sparingly because once the belt gets wet, you can’t pinpoint the culprit anymore until the belt dries off. IF indeed this is where the source of the squeal is coming from.

If the idler pulley bearing is worn out already (it could happen) the problem may be due to poor materials used.

It also may (possibly) be due to the pulley being turning on an angle, but not enough to throw the belt.

Up until the serpentine belt came to be, the different components (steering/water pump/A/C/cooling fan(s) were driven by separate belts. You could eliminate possible worn bearings/pulleys one by one.

Ensure ALL the pulleys are aligned. Use something for a straight edge that will reach from the top pulley to the bottom ones.

A carpenter’s square would be best but the shorter ‘L’ won’t allow you to get at the pulleys. You might try a ‘T’ square that is used on a drafting table.

One more thing now that I remember, if the water pump has never been replaced, I would suspect that may be failing.


Good suggestion, but I’m pretty sure it’s not that - and I know what you’re talking about because I replaced that part once already (the sensor AND the mangled sychro). Funny you mention this here, though, because the new part (which has been in there for about 4 years now) actually DID start chirping briefly about 18 months ago, but then stopped. I hope that’s not going to fail on me again. That synchro was $120 and the sensor was $35.


Another good idea. I’ll try that. And here’s another idea from someone on another board that I’m going to try: turn the serpentine belt around 180 degrees (take it off, turn it around, put it back on).

And it’s funny that you mention the water pump because mine is original and I KNOW it’s all corroded inside and needs to be replaced. Right now I’ve got very little (almost no) heat even after blowing out the heater core because I think the water pump has no power left and/or is forever discharging corrosion into the core.

Hey Roadrunner,

I haven’t been on the board for a while. Good to hear from you again!

Regarding the one-year old idler pulley bearing wearing out - I never greased that thing before it was pressed in. I remember looking at it and thinking it was a sealed ring - it didn’t look like it was possible to grease it. But maybe I should have tried??? Also, when the guy in the machine shop pressed it in he worried me a bit because he applied all the force at the center of the bearing instead of around the outer ring (using an oversized socket or piece of pipe). Do you think it’s possible he distorted the bearing from day 1 - and this is why the pulley never spun freely after bolting it on?

I’ll check pulley alignment, but last year everything looked pretty firm and straight, so it’s probably still good now.

Hi Colt,

Yes, it has been a while. I was a little surprised to see you post again.

The idler pulley never spun freely after bolting it on?! Did you personally try to spin it by hand yourself before the belt went back on?

OK or one of the other techs here could tell you for certain if the idler pulleys have packed bearings, I’m not positive but I would tend to think they are.

As I’ve said before, I’m no tech but I certainly would not use a driver with a smaller circumference than the bearing being set. It would be too easy to set it crooked (out of line), plus the grease would be able to leak out when it got hot.

CH, The Screwdriver Idea Suggested By Wizard Is Good. You Can Have Fun With An Automotive Stethoscope, Too.

I’ve had one for years. They work great. They work so well that you have to be careful you don’t bump the probe into anything when you’ve got the ear-pieces in your ears or it sounds like an explosion. I was just in the Big City last week-end, roaming through the Sears Tool Department. They had Craftsman ones for about $15-$20. Ask Santa for a set.

Colt Hero,

I remember replacing the tensioner on my 97 GL because the pivot point seized up on the tensioner, and would no longer hold proper tension on the belt, nor could it be sprung back to remove the belt. Dayco makes a after market tensioner for your car, and its available at most auto part store, if it turns out to be the problem.


I hope that’s not it, but thanks for the heads up. Someone of one of these boards mentioned that replacing the tensioner pulley is a major pain in the ###.


Just lost the post. Disappeared into thin air. Haven’t they fixed all the bugs on this board yet? Hasn’t it been about two years now since they changed the format (and ruined a good forum, in my opinion).

No, the idler pulley never spun freely (by hand) after bolting in on. I thought this was odd, but others assured me it was no big deal.

By “packed bearings” do you mean “pre-packed/greased by the manufacturer”??

Yeah - I’m really starting to think the new bearing was damaged on install a year ago. These bearings are amazingly flimsy. I think pressure applied in the wrong spot could easily distort either the ball bearings themselves or the race that they roll around in…

Not hard at all to replace. But you may need a large torx wrench to remove the bolt. The new tensioner will come with a conventional hex bolt that will replace the torx bolt. The new tensioner is easier to release the tension to get the belt on, only needing I think a 15mm box wrench.

If you can change a intake manifold gasket on a Impala you can do this :slight_smile:

Common sense answer:

(Yet another lost post … this is a cut/paste re-submission)…

I’ve seen that stethoscope and that’s exactly the one I had in mind. I was surprised how inexpensive it was.

Forget about Santa. I have a Charlie Brown Christmas every year.

There’s more bugs than what you see here.

Yes, by ‘packed bearings’ that is exactly what I meant.

AS you know I’m not a tech, but have used the screwdriver method myself over the years with a degree of success.

It takes a little while to become confident using such a tool for finding worn bearings as the noises moving components emit can be confusing unless the bearings are REALLY bad.

If they are that bad you won’t need a sensing tool.

I have also used (and still have) a aforementioned stethoscope.

When I replaced the idler pulley bearing last year, I had to use a standard box wrench to move the tensioner because that’s all I could get in there. There wasn’t much clearance. You really need a thin breaker-bar style wrench (which I think I saw at Sears but didn’t buy).

Yeah, since doing the intake gasket job I feel like I can do anything now, but that doesn’t mean a PITA repair still won’t strike some fear in me …

Ended up installing the Duralast aluminum unit. The old unit came out pretty much intact - no bearing issues and no vanes rusted off as others have mentioned. I DID notice, however, that if I held the unit up against the sky, hairline cracks could be seen through the bent edges of each vane. Hopefully this was affecting flow and my heat will be better now. Really hasn’t been cold enough here yet to prove this theory, though.

Used all the original factory hoses. Didn’t have time to look for replacements. Nothing is leaking so far. Tensioner seemed to be fine, as did all the pulleys - no loose ones or squeaking that I could discern. Tensioner required a T50 Torx bit which I had to purchase.

One issue afterwards: I was getting a fine vibration in the steering wheel when turning right sometimes. It seems to have gone away. It was a feeling very similar to what you feel when your passenger wheels roll over the corrogated pavement in the brakedown lane on the interstates. Maybe this was air in the power steering line? I never physically detached the Power Steering unit, though - just took it off the threaded studs and pushed it aside to give a better view to the water pump below.