Plastic Part That Runs The Serpentine Belt On A 1999 Chevy Malibu

[crashtech]

I'm not sure thinking of your car as a dangerous lemon is going to help all that much. This is a problem that can affect most vehicles. Also, composite pulleys aren't that rare either, and even metal pulleys will quickly throw off a belt when the bearing is seizing. I'm sorry it happened to you, but it's not really anything inherently wrong with the car.

 

[Drako]

I see the problem - "Made in Canada"

 

[LTC8K6]

The belt tensioner generally lasts a long time, and it generally gets noisy before it fails.

Your original one should have been replaced at some point during a tune-up or check up. It was likely making noise.

After all, the car is 16 years old.

The new tensioner (and engine) will likely last a long time.

I wouldn't worry about it failing any time soon.

Now is a good time to get familiar with what your engine sounds like, so that when a part starts making a noise, you will know to get it checked out.

 

[Linux23]

How can that part damage the motor?

 

[Ferzerp]

How can that part damage the motor?

If I had to guess, I would say losing a belt and then continuing to drive a substantial distance instead of immediately stopping.

 

[Ramses]

That roller is one of those parts that is a wear item that nobody ever replaces till it's worn out and melts or eats the belt or such. Usually in the rain, or at night, in the middle of nowhere, or in the rain at night in the middle of nowhere. What's worse is the frequency of obtaining crappy replacements. The $18 one at the McParts store is tempting but I've seen bearings pressed in crooked, bad plastic from worn molds, no lube in the bearings, etc, etc. I splurge on junk like that at the dealer when I can. It's still slightly preferable to tensioning and replacing V belts. It isn't specific to one car either, just as much grief from them on Fords as Mercedes back when they became common place.

 

[SparkyJJO]

I'd wager that thing was making noise for a while before it failed. They don't typically just suddenly fail without any warning at all.

A lot of vehicles from many brands have plastic idler pulleys. I don't care for that. I've always had metal idlers on my cars when I replace any because I don't trust the plastic one. Costs me $25 instead of $18. Usually they have them at the parts store, but if not I can always fine them on somewhere like Rock Auto online. Screw going to the dealer, costs more than it should and if the original was plastic there is a good chance the one from the dealer will be too.

I'm just curious how long you drove the car without a belt to have totally roasted the engine though

 

[videogames101]

You'll find that sometimes just looking under the hood you might not see all potential problems with an engine. One of the best ways to discover problems on belt systems is by listening. I highly recommend taking a good listen of everything your belts ride on, especially idlers. Use something like this (it's one of my favorite tools):

http://www.amazon.com/Lisle-52500-Mechanics-Stethoscope/dp/B0002SQYSM

You can place the end of the scope near each pulley on the belt and pretty much find any bearing that's about to go, or other problems. Once you identify the element on the belt which is grinding or sounds funky, you can decide if it's a likely point of failure.

For example, your idler pulley was probably making a whole lot of racket before it failed. I'm guessing it wouldn't have taken more than a few minutes listening around under the hood to hear something wrong with the idler. But it's not always something you can see just by looking. The only trick is knowing what sounds right and wrong, which I guess comes with a little practice.

 

[Linux23]

that's pretty cheap too. ^^^