Drive Belt Snapped -- Cause?

[Luigi]

Hey gang. My alternator drive belt broke this morning, thankfully just a few blocks from home while I was on my way to work. I was able to drive back home with no power steering, just on battery power, and before my car was fully warmed up and caring that the water pump was no longer turning!

So, when I replaced the water pump a year ago, I also replaced the idler pulley and belt tensioner pulley. Aside from "simply" it being a defective drive belt, can you think why else my drive belt would snap? I don't want to put a new one on only to have the same problem again down the road -- need to fix a cause, if there is one. Thanks.

[TRELO]

Remove the broken belt and turn the pulleys by hand. Seen a few e46s w locked up
Alternators. Could be a defective pulley you put or simply the belt.

Check for grinding or binding. Could be that wp too


Opa iPhone

[spencers]

Remove the broken belt and turn the pulleys by hand. Seen a few e46s w locked up
Alternators. Could be a defective pulley you put or simply the belt.

Exactly. Check those pulleys as well. Where were the pulleys purchased from?

Was the belt the same size as OEM?

[Luigi]

Nice, thanks TRELO -- I gave each the pulleys a cursory quick spin after I pulled the belt out and all spun fine -- didn't detect binding or grinding. Will check better once I'm home, though. But the locked up alternator -- come to think of it, I'm not sure I tried to turn its pulley. OK, got some troubleshooting work ahead of me. Power sterering pulley, water pump pulley, alternator pulley, idler pulley and belt tensioner pulley -- that's it, right? Ah, I hate this crap sometimes. Dang it all. Again, thanks for the help.

[Luigi]

Spencers, thanks much. Pulleys and belt from my local parts store -- not OEM. I held the old belt up against the new one to make sure it was the same length. Do you strongly recommend OEM belt? Not ready to deal with the pulleys again, quite yet.

[spencers]

I think if the replacement belt is within the OEM size by a couple millimeters, you should be fine. Personally, I like Gatorback belts.

Aside from spinning the pulleys, you also want to check for pulley wobble.. Try to wiggle it about its axis and look for play.

[Luigi]

All good stuff -- thanks much for taking the time to share your advice. I'll be trying all you recommend. Time to get the coveralls out and work gloves on.

The car was whisper quiet this morning, too. No squeaks or squeals ... hmmm. Just sudden battery light on, power steering bye, bye, and you know the rest.

[aurelius]

Power sterering pulley, water pump pulley, alternator pulley, idler pulley and belt tensioner pulley -- that's it, right?

There is also a pulley on the alternator. Haven't heard it's problematic but it is replaceable. How many miles on your car?

[danewilson77]

Search e46 pulleys on youtube and there will be a video showing you what to look for when inspecting your pulleys.

The pulleys should not spin freely, and should have some resistence...in a nutshell.

Droid + Tapatalk = FTW!

[Luigi]

Guys, thanks again for the additional replies and help! So appreciated. It's got 69,000 miles. Youtube, I'm there -- thanks!

This is weird because I've been working on cars since I could drive, but somehow I've escaped pulley and belt troubles until now! That's very strange to me ...