Hey guys! Me again, I've posted a few times before now, and I've got a new weird little problem.

With spring and summer coming up, I've started having to use my AC finally, so I'm only now noticing this issue. I replaced several pulleys in my car back in the winter months, including tensioner pulley, idler pulley and the alternator. Haven't had any problems with any of them, though my belt still squeaks when it's cold, but I'm chocking that up to the belt itself, or probably an oil leak I've just discovered in the oil cooler lines up near the radiator.

Anyway, with the AC on, when I rev even a little to start moving, or even sometimes when it idles, I'll get this little clattering sound from the engine. I've diagnosed it as the new tensioner pulley basically being pulled as far taut as it can possibly go, meeting a little tab stop on the pulley itself that keeps it from over extending and possibly throwing itself off. I've not had this issue before with the old pulley, so I'm not sure what's going on here. It places plenty of tension on the belt as far as I can tell, but as soon as the AC compressor kicks on, it's almost like this tensioner isn't as stiff as the old one.

Is there anything I can do for this? Or is this gonna require a different tensioner pulley? The pulley I bought is a Duramax tensioner from AutoZone. Do I need to look into an ACDelco instead?

Thanks for the help!

 

The belt itself may need replacing. They do stretch and wear out. Getting a faulty tensioner is plausible, could try old one if still laying around to confirm?

 

I want to kinda go with the belt being the issue as well, but the belt was new as of December of 2017, so its only 16 months used.

The old tensioner is gone, sadly. I had it for a while but spring cleaning in preperation to move saw me chucking it a couple weeks ago.

I might look into an ACDelco one, if ACDelco makes them at all, and see how it goes. It... I don't think it's a critical issue just yet, and I plan on replacing the belt with one of those people recommend around these parts to stop the squeaks, so I might just look into a better quality tensioner at that point.

 

You had not mentioned belt was replaced recently. Would agree being that new hardly seems likely unless a rather poor quality belt. Maybe just grab a tensioner from a bone yard as a cheap test, never priced one myself yet.

 

A dragging pulley will heat up the belt and cause it to stretch somewhat and can also glaze the inside - If nothing else take it off and compare it to a new one at a parts store...

And double check all pulleys, water pump ECT .as the least amount of drag will cause the tensioner to move.

I have also seen the unit be rotated and the mounting peg get missed in the hole and tension is low because of it.

 

I feel dumb now.

The idler pulley I pulled out about 5 months ago... Well, let's just say I'm really, really surprised it was still even remotely spinning when I pulled it. It was completely and utterly shot, and I believe it had been for about a month. The old tensioner also was shot, it wouldn't hold the belt hardly at all at some points, specially in the rain since my Blazer doesn't have an underside splash guard for whatever reason.

I should think logically, cause yeah, this belt is probably junk after all it's been through. Sorry to bother guys, I'll replace it ASAP lol.

 

Thanks for the update - luck to ya