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How to Properly Inspect your Engine Belts

Created on: 2018-03-06

How to check a squeaky or worn serpentine belt on 04 Subaru Impreza WRX.

  1. step 1 :Inspecting the Belt
    • Check the belt for wearing smooth
    • Check the belt for wearing rough
    • Look for cracks wearing in the rubber
    • Check the grooves for wear

Hi, I’m Mike from 1A Auto. We’ve been selling auto parts for over 30 years!

This particular vehicle doesn't use an auto tensioner for the belts. It has two separate drive belts, both with manual tensioners, so you need to adjust these and set your belt tension. And the same for the other one down here that runs the air conditioning pulley. And these belts feel fairly tight, but they are squealing. The belts do stretch over time. You could try to readjust them, but these are looking pretty worn. They've got a lot of rust staining on them. And basically every time you start the car when it's cold, they squeal really loudly. And once they start to squeal, they're kind of ruined.

We'll replace them with new belts from 1A Auto. Slide in between here. You can see some wear, it's kind of worn smooth, and the outside is pretty rough. This one does have some wearing. Where it's sliding on the pulleys and making noise, it almost looks like a tire, like you did a burn out with it. It kind of wears.

So here are some things to look for when you're inspecting your belts. When you're looking at dry belts under the hood of a car, you want to look for cracks like this, in the rubber. This belt is worn out. These little grooves can actually start to fall apart, and then the belt won't have any grooves on it, because they're all dry rotted and cracked. And the back of it is like real dry and worn, it has a little bit of fraying on the edges. So this belt, and you can feel it in this belt, and actually you can see it over here. Part of the ribs are starting to fall apart. And this belt is really hard, it's not very flexible. It's really past its prime. It needs to be replaced.

This one here was making noise. It was squealing. You can see that it's got like worn rubber marks. Like, it looks like a tire you were doing burn outs, or something. You get those worn tire marks, and the rubber wears. And it also has some fraying around the edges. And the grooves are kind of worn. So this belt is no good. If we compare it to a nice, new belt, it's really flexible, the grooves are nice and thick. They've got plenty of good rubber on them. There's no fraying or anything. And the other thing too, sometimes with a car that has an automatic tensioner, you won't hear the belt squeal as it starts to wear out, because the automatic tensioner will take up the slack, as the belt stretches. Whereas a belt that's on a manual tensioner, as it starts to wear it will start to slip. And then once it starts to slip, it kind of ruins the belt. You can try to re-tension it, but you should really just replace it. When the new belt is replaced, the embarrassing squealing noise is now gone.

Thanks for watching. Visit us at 1AAuto.com for quality auto parts, fast and free shipping, and the best customer service in the industry.


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