Belt tensioner problems?

[96B-Mike]

My belt tensioner has been rattling loud for quite some time..so I installed a new one and it was quiet for maybe a week? At first I thought the loud noise was my a/c clutch or the compressor itself..

My mechanic had a mechanic type of stethoscope and said the noise is only coming from the tensioner..(fyi I replaced the tensioner twice)

Any ideas..would you like. A video?

[DTMAce]

Bad belt, or incorrect belt possibly. Or you have had bad luck several times. Jingling noises would be the A/C bearing though.

[beretta]

if it were the bearings in the A/C compressor would it rattle if the clutch was engaged ? maybe test it with the A/C on and see if the noise stays the same.

My cars been making some noise for a while, i have a new belt tensioner and water pump but havent gotten around to changing them yet, i should do so soon my belt is cracked pretty bad kinda surprised its still holding on.

[DTMAce]

Actually engaging the A/C by using Defrost or A/C (providing your system is charged and working properly) will cause the pump to run and will make the ringing noise stop.

You have to think, the pulley rides on a bearing when the A/C pump is not engaged. THAT bearing tends to go bad and when it does, it starts making jingling sounds. When you engage the pump however, the bearing stops turning as then you are turning the entire pump itself, so the noise stops. But if your refrigerant is not properly charged or depleted, the pump will never engage no matter what setting you put it on.

And trust me, when that bearing does go, it may even keep you from starting your car at all. It will prevent the engine from cranking. I know from experience. hahahah

[3X00-Modified]

Actually part of that is true... but some isn't. The bearing itself is not making that noise its two parts touching that shouldn't and the distance betwee those two parts when the bearing is good is VERY little so it doesn't take much to "go bad."

The jingle is the sound of the main pulley of the AC compressor touching the AC clutch plate. When the pulley bearing goes bad that pulley will wobble and touch the clutch plate part of the compressor (the part you see not spinning unless the AC is engaged) When it touches that, the pulley will then make that ring/jingle sound due to how it is made (tap a AC compressor pulley with a screw driver some day it will make a similar sound), when the AC is engaged the AC coil behind the pulley pulls the clutch of the AC compressor into the pulley itself which makes the compressor turn at the same speed... Now note that the "bad bearing" is still spinning but what was causing the pulley to jingle is now pressed against it and not just touching it as it spins. Image below to see the part makeup.

[96B-Mike]

so you saying that the cause of the rattling of the belt tensioner is the a/c compressor?

[DTMAce]

No, we are saying that is one possible cause for the noise.

[96B-Mike]

hmm kk..fyi guys my a/c blows cool..just saying if it makes a difference...and the belt tensioner rattles louder when the a/c is on

[3X00-Modified]

Well then stop buying cheap tensioners if they keep failing like this. I'd get a new one from a different parts supplier.

[96B-Mike]

? i get em at a auto parts store? i dont really think there is a "higher brand"?

[3X00-Modified]

Rock auto lists Dorman, Dayco, Godyear, Gates, Hayden, ACDelco, and Four Seasons... You said you've replaced it once already and its still making the same noise so as we've suggested you need to research else where and see if something else is causing the noise, but if your dead set on it being the tensioner then change the brand you bought.

[DTMAce]

More likely, if you are sure its the tensioner, then there are only 4 possibles I can think of that would be causing the issue:

1: Defective or not built to factory specs brand of tensioner.
2: Incorrect belt. (thickness, width, length)
3: Defective belt. (pieces missing, cracks, fluid contamination, etc)
3: Incorrectly mounted tensioner.

If you are certain the noise IS the tensioner, then I can only point to one of those things being the culprit. Outside of that, one of your other accessories or pulleys is doing something to the belt path or causing damage to the tensioner somehow, but I don't really see how.

[96B-Mike]

aight well now i just changed the belt tensioner again and its sounding great..no vibrations at all..I"ll just see from here on out if it acts up again