2001 Corolla/Prizm and intermittent squealing sound

This concerns a 2001 Chevrolet Prizm (essentially the same thing as a 2001 Toyota Corolla).
An intermittent, high-pitched squeak/squeal is coming from the
left-hand side of the engine compartment, where the drive belt (aka "fan belt" or "serpentine belt") is located. This seemed to have suddenly started after the vehicle hadn't been driven for a month. It's also possible that it was happening before but I just didn't notice it. The noise goes away when accelerating and comes back (sometimes) when decelerating or maintaining a steady speed. Also, initially the squeal was heard quite frequently. However, I have taken this Prizm on several short test drives since I first noticed the noise, and the intermittent squealing seems to be getting less and less frequent with each test drive. It's almost as if the short test drives are helping to loosen something up, though that's just a guess.
Anybody have an idea about what could be causing the squealing noise? A friend suggested that it might be due to a loose belt, but I doubt that. I'd expect a squealing belt to get noisier during acceleration, not quieter.
Okay, I need to add a few things because the picture changed a little during my most recent test drive (made after I started writing this). The squealing doesn't always go away during acceleration. But it does seem to occur less frequently during acceleration. And I should also mention that sometimes the squeal has a definite rhythm to it when the engine is idling. At one point it sounded something like this: squeak-squeak-SQUEAK (pause), squeak-squeak-SQUEAK (pause), squeak-squeak-SQUEAK (pause)... In other words, two short squeaks followed by a longer and louder one.
Phil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Not necessarily. The first thing I would check would be the condition and the tension of all of the belts. Change any worn or cracked belts.
The next most likely culprit is the serpentine belt tensioner idler. This is an idler that simply bolts onto the tensioner and is easy to replace. They normally make more of a growl than a squeal, but it's not beyond reason at all to expect a squeal.

I'd go with the idler - but first check the condition of those belts.
--

-Mike-
snipped-for-privacy@alltel.net
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike Marlow wrote:

The serpentine belt looks fine, and it doesn't seem loose. Although I didn't mention in my post, checking the belt was one of the first things I did. I also checked the alternator using a piece of vinyl tubing as a crude stethoscope, and ruled it out as the source of the noise. Now I am going to do the same thing (CAREFULLY!) with the belt tensioner. I'm also going to get out a bright light and take another look at the belt, just in case.
Phil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Also make sure that the belt is not glazed or shiny. Check both the inside and outside surfaces of the belts. A worn belt is not always obvious. When checking for belt wear, make sure that the angle part of the fits the profile of the pulley and contacts evenly.

On a serpentine belt, make sure that all of the pulley, idlers, tensioners, etc. are on the same plane. If one or more pulley is not on the same plane, then the pulley and/or belt may make noise when passing through that pulley.
--

Ray O
(correct punctuation to reply)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ray O wrote:

The belt isn't glazed, but I did notice that it seems to have a fair amount of powdered rust on it. The car sat for over a month, and during that time we had a tremendous amount of rain. The humidity is very high at this time of the year, too. I am wondering if the powdered rust could be acting like a dry lubricant and causing the belt to slip a little every now and then.

Actually, this could have a lot to do with it. I read that the 1998 to 2001 Corollas all have a problem with the belt alignment. Supposedly, the easiest fix is to remove the pulley from the alternator and put a shim behind it. Search Google Groups ( http://groups.google.com/ ) using these keywords: corolla squeal shim letter. One of the posts listed will be called "My Letter To Toyota..."-- that's the one you want.
Phil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That is a possibility. Another possibility is that the dust has contaminated a pulley bearing somewhere.
A competent shop will have a belt tension gauge and can tell whether it is too tight or too loose.

I'm aware of the problem, which is why I brought it up ;-)
--

Ray O
(correct punctuation to reply)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@rocketmail.com wrote:

What you are most likely experiencing is serpentine belt squeal caused by a worn leaking "shock absorber" on the tensioner assembly. One quick visual check would be to look at the top of the vertical "shock" for signs of oil leakage. Any oil is too much. You could also put a 19mm wrench on the adjuster lug and compress/release the tension to see if there was any hydraulic resistance. No resistance indicates a dry shock. This is very common on the 1ZZ-FE engine.
If you should need to change the tensioner, get a new belt at the same time (generic belt size code = 6PK1890 in metric length; 4060744 or 744K6 in common inch length terms). The tensioner is pricy. Originally, there were two tensioner manufacturers supplying Toyota for this part. After the problems became evident, Toyota changed all of their stock to the one manufacturer that was making them better. (This is my educated guess on the supply situation)
Further, a bad tensioner usually makes a knocking type noise mostly at idle with trans in gear. This is a dead giveaway.
If your tensioner is OK then replace the belt only as long as you are sure that the squealing is coming from that area. Oddball causes of belt squeal other than a bad belt or tensioner include overcharging alternator, bad accessory bearing, misaligned pulley(s), or wrong belt. Every once in a while I come across an aftermarket belt that is the correct length but there is something different about the cross section of the ribs that causes it to be noisy. Keep this in mind before you chase your tail too much.
Clean the rust powder off of the pulleys with a still wire brush before any parts replacement.
BTW, the Chevy Prizm adds a neat twist to tensioner replacement. They use an accumulator A/C system (I guess the Nippondenso drier system cost too much for the Chevy version). Anyhoo, the accumulator and suction piping really gets in the way during removal.
Toyota MDT in MO
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@rocketmail.com wrote:

Sorry, when I typed "Clean the rust powder off of the pulleys with a still wire brush...", I meant STIFF wire brush. If you used a *still* wire brush you'd never make any headway!
Toyota MDT in MO
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'm not a mechanic, but I would first check and see how loose the belts are. After that I would go to auto zone and get some stuff that they make to lessen belt noise. I can't remember the name of it though. If the noise still is going on, I would look at the things that the drive belts are attached to and make sure that they are in good working order.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

are.
Sorry - but I'd stay far away from Belt-Ease and all the like products. If the belts are worn, replace them.
--

-Mike-
snipped-for-privacy@alltel.net
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

are.
Be careful about using the belt dressing for noisy belts. Many here would recommend staying away from that sort of product. There have been a lot of bad experiences using that stuff, especially on serpentine belts.
--
Kevin Mouton
Automotive Technology Instructor
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks for the advice on the belt dressing...I've never used the stuff myself, but I heard it was good.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'm sure Kevin & I both have seen instances where belt dressing has actually caused v-belts, at least, to sound just like a bad power steering pump. IMO, that stuff is good to avoid. A squealing belt indicates something is wrong. s
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

<snipped>
In 35 years working on cars, (15 years working for a company that makes cars) I've never used belt dressing. IMO, using belt dressing is like giving methadone to a heroin addict - it hides the symptoms but doesn't cure the root cause.
--

Ray O
(correct punctuation to reply)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 12 Jul 2006 11:47:02 -0500, "Reasoned Insanity"

If you were a mechanic you would not do this.
Don www.donsautomotive.com

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

LOL!
That's especially freakin funny because I'm a gearhead from way back, but due to time constraints Don maintains my wife's car (the PO took the car to him as well). The man would most *definitely* not do this.
Don is knowledgable, conscientious and honest. The last repair included rebuilding the distributor vacuum advance - many mechs would have sold her a new distributor. -- Mike Harris 1987 Corolla hatchback Austin, TX
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.