Another Serpentine Belt Failure

illrider · 06-05-2015, 09:52 PM

I was driving to work this morning on the freeway and had my battery charge alert light come on and then luckily I noticed my power steering was out before I tried to make any exits off the freeway. I just had the belt replaced last year, so about 12-15k miles and it has broken again already. So of course I did some reading to find out what might be causing this as it should last a lot longer. First thing I checked was the alternator pulley. Stuck a flat head screwdriver in there and tried to rotate the pulley and it was locked up and would not rotate in either direction. That relieved me to know i found what was most likely the issue right away. I went ahead and started removing the belt and inspected all the pulleys to find that my power steering pulley now only had two bolts holding it on and the two bolts were loose, allowing the pulley about .5"-1" of play! Well that would obviously cause an issue as well!

I am obviously replacing the alternator pulley for sure, but I'm not sure if I need to replace any of the other pulleys as well. Looking for some advice.

Power Steering Pulley (see picture below) There is some minor chipping/flaking on the inside of the pulley between the bolt holes. It is not very deep and does not seem like it would affect the integrity of the pulley, so I was thinking about just reusing it. Thoughts?

Belt Tensioner - When I rotate the tensioner one direction it rotates smoothly. When I rotate it the other direction I hear what sounds like a light "ticking" noise. I don't believe that it should be making any noise in any direction and should rotate freely and quietly. Could anyone please confirm this?

The Pulley below the tensioner (picture below) There is some "rubber burn" and crud on the pulley from the belt spinning around and melting on it. It seems to scrap off fairly easily with a flat tip screw driver. Can I clean it off and reuse it? Or Should I replace it?

Thanks for the help you guys!

p.s. Where do you guys recommend ordering pulleys from?

Nitrousbird · 06-05-2015, 10:25 PM

Change your motor mounts. Motor movement could be causing the belt to strike the subframe, which is why there is an updated subframe for our cars (previous owner of line shelled out a fortune for a subframe swap due to a belt shredding problem).

gabylonfive · 06-05-2015, 11:27 PM

If I were you I would just replace all of them, you'll already be in there and the parts are cheap. Alternator pulley, tensioner, upper and lower idlers, and ps pulley. Do not reuse that ps pulley.

Like noted above, I would replace your motor mounts asap, get the 335is passenger mount as its a bit stiffer. Just replaced mine (and all the parts above) as my ps pulley kissed my subframe after hitting a fairly large pothole and took a nice bite out of the pulley. Luckily no damage to the belt but I will take no more chances with my belt getting shredded and sucked in through the front seal.

illrider · 06-06-2015, 12:12 PM

Can anyone help me out with a link to the correct alternator pulley tool?

Spacecpe · 06-07-2015, 04:45 PM

Link for the tool

http://www.amazon.ca/CTA-Tools-8088-.../dp/B005OH0LU8

Spacecpe · 06-07-2015, 04:56 PM

I had this happen for the 3rd time in my case a couple weeks ago .. First time was last summer, shape replaced the belt only and everything was back to normal .. 6 months later the belt shredds again and this time goes through the crank seal ( luckily I shut the car down right away and the belt didn't make the chain skip thank god. Cost me 3800$ to pull the oil pan an clean everything up). 3rd time was a couple weeks ago when I was cruising in 3rd gear doing maybe 30mph and I heard a weird noise stopped right away and looked under the hood and the belt was half gone. So this time I decided to do the work my self. Pulled all the pulleys and checked for damage, idler pulleys were pretty worn and tensioner too, the pa pulley was intact looked brand new ( was never replaced ), and when I checked the alternator pulley to my surprise it was locking on both ways ( it should spin when you turn it left while the alternator is locked ). So to my guess the shop never checked the alternator pulley and that's what's been causing this as my car is an 09 production and there's absolutely no marks of the pulley coming in contact with subframe. So to all the members that have this happening check your alternator pulley and you ps pump or pulley for loose bolts if you don't see any contact with the subframe. Car has been off the road for 2 weeks now waiting for parts because the damn alternator pulley is back ordered.

06-05-2015, 09:52 PM	#1
illrider Second Lieutenant 26 Rep 215 Posts Drives: 08 E90 Join Date: Jul 2011 Location: Mesa, AZ iTrader: (1)	Another Serpentine Belt Failure I was driving to work this morning on the freeway and had my battery charge alert light come on and then luckily I noticed my power steering was out before I tried to make any exits off the freeway. I just had the belt replaced last year, so about 12-15k miles and it has broken again already. So of course I did some reading to find out what might be causing this as it should last a lot longer. First thing I checked was the alternator pulley. Stuck a flat head screwdriver in there and tried to rotate the pulley and it was locked up and would not rotate in either direction. That relieved me to know i found what was most likely the issue right away. I went ahead and started removing the belt and inspected all the pulleys to find that my power steering pulley now only had two bolts holding it on and the two bolts were loose, allowing the pulley about .5"-1" of play! Well that would obviously cause an issue as well! I am obviously replacing the alternator pulley for sure, but I'm not sure if I need to replace any of the other pulleys as well. Looking for some advice. Power Steering Pulley (see picture below) There is some minor chipping/flaking on the inside of the pulley between the bolt holes. It is not very deep and does not seem like it would affect the integrity of the pulley, so I was thinking about just reusing it. Thoughts? Belt Tensioner - When I rotate the tensioner one direction it rotates smoothly. When I rotate it the other direction I hear what sounds like a light "ticking" noise. I don't believe that it should be making any noise in any direction and should rotate freely and quietly. Could anyone please confirm this? The Pulley below the tensioner (picture below) There is some "rubber burn" and crud on the pulley from the belt spinning around and melting on it. It seems to scrap off fairly easily with a flat tip screw driver. Can I clean it off and reuse it? Or Should I replace it? Thanks for the help you guys! p.s. Where do you guys recommend ordering pulleys from? Attached Images
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06-05-2015, 10:25 PM	#2
Nitrousbird Banned 432 Rep 1,602 Posts Drives: '07 E92 335i 6MT Join Date: Dec 2014 Location: Powell, OH iTrader: (2)	Change your motor mounts. Motor movement could be causing the belt to strike the subframe, which is why there is an updated subframe for our cars (previous owner of line shelled out a fortune for a subframe swap due to a belt shredding problem).
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06-05-2015, 11:27 PM	#3
gabylonfive First Lieutenant 52 Rep 335 Posts Drives: 04 M3, 05 Elise Join Date: Oct 2013 Location: Bay Area, CA iTrader: (3)	If I were you I would just replace all of them, you'll already be in there and the parts are cheap. Alternator pulley, tensioner, upper and lower idlers, and ps pulley. Do not reuse that ps pulley. Like noted above, I would replace your motor mounts asap, get the 335is passenger mount as its a bit stiffer. Just replaced mine (and all the parts above) as my ps pulley kissed my subframe after hitting a fairly large pothole and took a nice bite out of the pulley. Luckily no damage to the belt but I will take no more chances with my belt getting shredded and sucked in through the front seal.
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06-06-2015, 12:12 PM	#4
illrider Second Lieutenant 26 Rep 215 Posts Drives: 08 E90 Join Date: Jul 2011 Location: Mesa, AZ iTrader: (1)	Can anyone help me out with a link to the correct alternator pulley tool?
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06-07-2015, 04:45 PM	#5
Spacecpe First Lieutenant 44 Rep 359 Posts Drives: E90 335i Msport Join Date: Sep 2014 Location: Winnipeg, Mb Canada iTrader: (0)	Link for the tool http://www.amazon.ca/CTA-Tools-8088-.../dp/B005OH0LU8
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06-07-2015, 04:56 PM	#6
Spacecpe First Lieutenant 44 Rep 359 Posts Drives: E90 335i Msport Join Date: Sep 2014 Location: Winnipeg, Mb Canada iTrader: (0)	I had this happen for the 3rd time in my case a couple weeks ago .. First time was last summer, shape replaced the belt only and everything was back to normal .. 6 months later the belt shredds again and this time goes through the crank seal ( luckily I shut the car down right away and the belt didn't make the chain skip thank god. Cost me 3800$ to pull the oil pan an clean everything up). 3rd time was a couple weeks ago when I was cruising in 3rd gear doing maybe 30mph and I heard a weird noise stopped right away and looked under the hood and the belt was half gone. So this time I decided to do the work my self. Pulled all the pulleys and checked for damage, idler pulleys were pretty worn and tensioner too, the pa pulley was intact looked brand new ( was never replaced ), and when I checked the alternator pulley to my surprise it was locking on both ways ( it should spin when you turn it left while the alternator is locked ). So to my guess the shop never checked the alternator pulley and that's what's been causing this as my car is an 09 production and there's absolutely no marks of the pulley coming in contact with subframe. So to all the members that have this happening check your alternator pulley and you ps pump or pulley for loose bolts if you don't see any contact with the subframe. Car has been off the road for 2 weeks now waiting for parts because the damn alternator pulley is back ordered.
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