Oh noes! Serpentine belt failure, tensioner weirdness!!

[ProZak]

Hi, everybody. Long time no post. Hope you're all well.

I am having the worst car month ever. First her minivan's transmission blows up, then my little Integra spins a bearing, and finally I can't keep a serpentine belt on either E34. I think I know what the problem is on the manual (need to get a bolt on the alternator tightened and eliminate play) but on the automatic I'm stumped. It's been sitting for a couple of months without belts on it for no particular reason but since it was the last running vehicle I owned I replaced the S-belt with a new Conti and the idler pulley in front of the alternator. Belt burned up in less than 1000 miles and the tensioner pulley is actually touching the idler pulley. ??? Is the tensioner spring loaded or hydraulic, and would not having a belt on it cause it to over-extend like that? Or is my idler pulley out of whack? Pics follow later this morning once I figure out my photobucket password.

Thanks in advance, all.

[632 Regal]

sounds like the belt is too long, or you routed the belt wrong.

[russiankid]

I put in a new mechanical tensioner from autohaus and when there is no belt its almost touching the idler pulley. Haven't had a problem yet in 6k miles.

[whiskychaser]

and the tensioner pulley is actually touching the idler pulley. ??? Is the tensioner spring loaded or hydraulic, and would not having a belt on it cause it to over-extend like that? Or is my idler pulley out of whack?
Just checked mine and can easily get my fingers between the two pulleys. My guess is the gap is about 3/4". The tensioner is hydraulic on mine. To give you an idea of tension, with the belt fitted to all the other pulleys and pulled tight it comes to about 1/3 of the way across the tensioner pulley. So you have to deflect the tensioner a good couple of inches to get the belt on. HTH

[Ross]

If the pulleys are that close with the belt installed the belt is too long or incorrectly routed. Check the other accessories to see how freely they turn, a bearing about to seize will cause the belt to drag. Any noises? An overcharged a/c makes the compressor work VERY hard too.

[sbihue]

Hi, everybody. Long time no post. Hope you're all well.

I am having the worst car month ever. First her minivan's transmission blows up, then my little Integra spins a bearing, and finally I can't keep a serpentine belt on either E34. I think I know what the problem is on the manual (need to get a bolt on the alternator tightened and eliminate play) but on the automatic I'm stumped. It's been sitting for a couple of months without belts on it for no particular reason but since it was the last running vehicle I owned I replaced the S-belt with a new Conti and the idler pulley in front of the alternator. Belt burned up in less than 1000 miles and the tensioner pulley is actually touching the idler pulley. ??? Is the tensioner spring loaded or hydraulic, and would not having a belt on it cause it to over-extend like that? Or is my idler pulley out of whack? Pics follow later this morning once I figure out my photobucket password.

Thanks in advance, all.

I just did this on my car. It has a mechanical pulley awhich was subsequently ended by BMW and replaced with a Hydraulic one. Which one are you using?

On one of the other boards, it was reported that the switch from mechanical to Hydraulic had caused issues for some with extra force being exerted on the tensioner housing breaking it along with the oil-filter housing ($$$) where it sits.

[genphreak]

Oh great, something else different on the same damned car. I have an 88 M30, a 90 M50 and a 95 M50. Nothing is the same on any of them other than the doors, the dash, the body and the freaking lights. So much for my idea that one car, one box of spares would still apply and create an economy of scale...