serpentine belt snapped while driving
#26
MBWorld Fanatic!
I have 78k miles on mine and as you can see from the belt pics it looks decent. All the idler pulleys spin freely without any noise and the tensioner felt strong.
#27
MBWorld Fanatic!
While it was a long time ago belts like women in a bar can be deceiving!
I am not sure I know what year your car is but if it is a 2009 or so I would not be trusting appearances. The belt is cheap insurance.
I am not sure I know what year your car is but if it is a 2009 or so I would not be trusting appearances. The belt is cheap insurance.
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hachiroku (07-20-2017)
#29
MBWorld Fanatic!
My belt sheared last might 100 miles away from home. I wasn't impressed.
Car was towed to MB today for diagnosis on Monday. I'm hoping it's just an idler pulley and replacement belt. I noticed some light puddles of fluid under the car whenever we moved it in stages onto the tow truck
Car has 91k miles on it.
Car was towed to MB today for diagnosis on Monday. I'm hoping it's just an idler pulley and replacement belt. I noticed some light puddles of fluid under the car whenever we moved it in stages onto the tow truck
Car has 91k miles on it.
#30
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a unicorn tuned p30 e63
My belt sheared last might 100 miles away from home. I wasn't impressed.
Car was towed to MB today for diagnosis on Monday. I'm hoping it's just an idler pulley and replacement belt. I noticed some light puddles of fluid under the car whenever we moved it in stages onto the tow truck
Car has 91k miles on it.
Car was towed to MB today for diagnosis on Monday. I'm hoping it's just an idler pulley and replacement belt. I noticed some light puddles of fluid under the car whenever we moved it in stages onto the tow truck
Car has 91k miles on it.
#31
Senior Member
My belt sheared last might 100 miles away from home. I wasn't impressed.
Car was towed to MB today for diagnosis on Monday. I'm hoping it's just an idler pulley and replacement belt. I noticed some light puddles of fluid under the car whenever we moved it in stages onto the tow truck
Car has 91k miles on it.
Car was towed to MB today for diagnosis on Monday. I'm hoping it's just an idler pulley and replacement belt. I noticed some light puddles of fluid under the car whenever we moved it in stages onto the tow truck
Car has 91k miles on it.
#32
MBWorld Fanatic!
Thanks mayn...
That would really hurt...
For what it's worth, when i had a look under the hood, the belt was still somewhat in one piece and fitted around the pullies...it was just ripped up and looking like a cat had gotten really pissed with it. I'm hoping it's just an idler pulley that seized, but life might not be that kind. Annoyingly i was having such a nice drive as well and the car was feeling so strong. I guess i'll know more in a couple of days.
For what it's worth, when i had a look under the hood, the belt was still somewhat in one piece and fitted around the pullies...it was just ripped up and looking like a cat had gotten really pissed with it. I'm hoping it's just an idler pulley that seized, but life might not be that kind. Annoyingly i was having such a nice drive as well and the car was feeling so strong. I guess i'll know more in a couple of days.
#34
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
Another reminder to check the drive belt and pulleys on a regular basis. I have it on my list to change them with billet pulleys and this winter layoff it will be.
#35
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2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Sorry to hear man, and just when you had the car performing well. That belt whipping around could have easily cut a coolant or oil hose. Highly doubt any fluid loss would be from anything other than that. Hope it’s an easy fix.
#36
MBWorld Fanatic!
Been AWOL lately and busy with work etc but at least I've somewhat fixed the car now.
So MB had a look and said that the belt had caused a light chip to the outer edge/lip of the AC pulley and they would need to replace the entire unit, as they don't sell the pulley for it....this, along with just the two failed pulleys was billed to me at £2,400GBP ($3,200USD). Needless to say I asked for the car back and paid them for their one hour of diagnosis (which probably took all of 5 minutes anyway.
So, with the car home, and on the driveway for my own inspection, I was greeted with a belt that looked rather sorry for itself (notice the really low coolant reservoir though) :
The top left idler pulley is the one that totally seized, but it also resulted in the pulley next to it getting all hot under the collar and taking it's top off, although it hadn't actually seized.
Comparing the old pulley to the replacement
You can see here, the plastic melted which caused it to come off the inside metal area
I was going to buy the billet pulleys that Shardul sells, but sadly stock availability at the time and international postage/customs etc would have meant 2-3 weeks of down-time which I didn't want, because I was having lots of fun with my HP tuners thing in my spare time. So I went to my local MB parts dept and the guy had them all in stock - awesome. Seeing as ALL of my pulleys needed replacing, I decided to do the whole lot (unlike the dealer whom only wanted to replace the two failed items). MB don't sell the tensioner pulley on it's own, but you can get a Gates pulley from eBay, which I did and it will probably arrive with me tomorrow I think.
For those of you wondering how/why I said they all needed replacing - remove your serpentine belt and try to spin the idler pulleys with your fingers. If they spin freely and/or make any form of sound, the road to failure has begun and you should replace them. Mine were all pretty bad and loud. I wonder if my alternator will charge my battery a little better now...it used to only manage little over 12V while the engine was running...maybe there was belt slippage going on.
Anyway, worth noting that one of the pulleys has been updated - refer to the part number and match the location with the diagram:
I'll wait till the tensioner pulley is fitted before taking the car for a drive. However I'm a bit concerned as to where the coolant has gone all of a sudden because I can't see any leaks on the ground after starting the engine and allowing it to idle for a bit. Hopefully there's a split hose somewhere that I haven't seen yet.
Oh and I almost forgot...the DIY repair cost just ~£190GBP. Crazy difference, huh?
So MB had a look and said that the belt had caused a light chip to the outer edge/lip of the AC pulley and they would need to replace the entire unit, as they don't sell the pulley for it....this, along with just the two failed pulleys was billed to me at £2,400GBP ($3,200USD). Needless to say I asked for the car back and paid them for their one hour of diagnosis (which probably took all of 5 minutes anyway.
So, with the car home, and on the driveway for my own inspection, I was greeted with a belt that looked rather sorry for itself (notice the really low coolant reservoir though) :
The top left idler pulley is the one that totally seized, but it also resulted in the pulley next to it getting all hot under the collar and taking it's top off, although it hadn't actually seized.
Comparing the old pulley to the replacement
You can see here, the plastic melted which caused it to come off the inside metal area
I was going to buy the billet pulleys that Shardul sells, but sadly stock availability at the time and international postage/customs etc would have meant 2-3 weeks of down-time which I didn't want, because I was having lots of fun with my HP tuners thing in my spare time. So I went to my local MB parts dept and the guy had them all in stock - awesome. Seeing as ALL of my pulleys needed replacing, I decided to do the whole lot (unlike the dealer whom only wanted to replace the two failed items). MB don't sell the tensioner pulley on it's own, but you can get a Gates pulley from eBay, which I did and it will probably arrive with me tomorrow I think.
For those of you wondering how/why I said they all needed replacing - remove your serpentine belt and try to spin the idler pulleys with your fingers. If they spin freely and/or make any form of sound, the road to failure has begun and you should replace them. Mine were all pretty bad and loud. I wonder if my alternator will charge my battery a little better now...it used to only manage little over 12V while the engine was running...maybe there was belt slippage going on.
Anyway, worth noting that one of the pulleys has been updated - refer to the part number and match the location with the diagram:
I'll wait till the tensioner pulley is fitted before taking the car for a drive. However I'm a bit concerned as to where the coolant has gone all of a sudden because I can't see any leaks on the ground after starting the engine and allowing it to idle for a bit. Hopefully there's a split hose somewhere that I haven't seen yet.
Oh and I almost forgot...the DIY repair cost just ~£190GBP. Crazy difference, huh?
#37
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Location: Orlando FL
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a unicorn tuned p30 e63
Been AWOL lately and busy with work etc but at least I've somewhat fixed the car now.
So MB had a look and said that the belt had caused a light chip to the outer edge/lip of the AC pulley and they would need to replace the entire unit, as they don't sell the pulley for it....this, along with just the two failed pulleys was billed to me at £2,400GBP ($3,200USD). Needless to say I asked for the car back and paid them for their one hour of diagnosis (which probably took all of 5 minutes anyway.
So, with the car home, and on the driveway for my own inspection, I was greeted with a belt that looked rather sorry for itself (notice the really low coolant reservoir though) :
The top left idler pulley is the one that totally seized, but it also resulted in the pulley next to it getting all hot under the collar and taking it's top off, although it hadn't actually seized.
Comparing the old pulley to the replacement
You can see here, the plastic melted which caused it to come off the inside metal area
I was going to buy the billet pulleys that Shardul sells, but sadly stock availability at the time and international postage/customs etc would have meant 2-3 weeks of down-time which I didn't want, because I was having lots of fun with my HP tuners thing in my spare time. So I went to my local MB parts dept and the guy had them all in stock - awesome. Seeing as ALL of my pulleys needed replacing, I decided to do the whole lot (unlike the dealer whom only wanted to replace the two failed items). MB don't sell the tensioner pulley on it's own, but you can get a Gates pulley from eBay, which I did and it will probably arrive with me tomorrow I think.
For those of you wondering how/why I said they all needed replacing - remove your serpentine belt and try to spin the idler pulleys with your fingers. If they spin freely and/or make any form of sound, the road to failure has begun and you should replace them. Mine were all pretty bad and loud. I wonder if my alternator will charge my battery a little better now...it used to only manage little over 12V while the engine was running...maybe there was belt slippage going on.
Anyway, worth noting that one of the pulleys has been updated - refer to the part number and match the location with the diagram:
I'll wait till the tensioner pulley is fitted before taking the car for a drive. However I'm a bit concerned as to where the coolant has gone all of a sudden because I can't see any leaks on the ground after starting the engine and allowing it to idle for a bit. Hopefully there's a split hose somewhere that I haven't seen yet.
Oh and I almost forgot...the DIY repair cost just ~£190GBP. Crazy difference, huh?
So MB had a look and said that the belt had caused a light chip to the outer edge/lip of the AC pulley and they would need to replace the entire unit, as they don't sell the pulley for it....this, along with just the two failed pulleys was billed to me at £2,400GBP ($3,200USD). Needless to say I asked for the car back and paid them for their one hour of diagnosis (which probably took all of 5 minutes anyway.
So, with the car home, and on the driveway for my own inspection, I was greeted with a belt that looked rather sorry for itself (notice the really low coolant reservoir though) :
The top left idler pulley is the one that totally seized, but it also resulted in the pulley next to it getting all hot under the collar and taking it's top off, although it hadn't actually seized.
Comparing the old pulley to the replacement
You can see here, the plastic melted which caused it to come off the inside metal area
I was going to buy the billet pulleys that Shardul sells, but sadly stock availability at the time and international postage/customs etc would have meant 2-3 weeks of down-time which I didn't want, because I was having lots of fun with my HP tuners thing in my spare time. So I went to my local MB parts dept and the guy had them all in stock - awesome. Seeing as ALL of my pulleys needed replacing, I decided to do the whole lot (unlike the dealer whom only wanted to replace the two failed items). MB don't sell the tensioner pulley on it's own, but you can get a Gates pulley from eBay, which I did and it will probably arrive with me tomorrow I think.
For those of you wondering how/why I said they all needed replacing - remove your serpentine belt and try to spin the idler pulleys with your fingers. If they spin freely and/or make any form of sound, the road to failure has begun and you should replace them. Mine were all pretty bad and loud. I wonder if my alternator will charge my battery a little better now...it used to only manage little over 12V while the engine was running...maybe there was belt slippage going on.
Anyway, worth noting that one of the pulleys has been updated - refer to the part number and match the location with the diagram:
I'll wait till the tensioner pulley is fitted before taking the car for a drive. However I'm a bit concerned as to where the coolant has gone all of a sudden because I can't see any leaks on the ground after starting the engine and allowing it to idle for a bit. Hopefully there's a split hose somewhere that I haven't seen yet.
Oh and I almost forgot...the DIY repair cost just ~£190GBP. Crazy difference, huh?
LOOK AT THAT E39!
#39
MBWorld Fanatic!
I'm curious if it was actually the plastic that failed which ended up wrecking the bearing in the process?
I checked mine when I did my belt a few months back. They all spin without grinding but I'm going to swap them all out anyway. I'm up over 130K km now.
Edit: Fixed the stupid...
I checked mine when I did my belt a few months back. They all spin without grinding but I'm going to swap them all out anyway. I'm up over 130K km now.
Edit: Fixed the stupid...
Last edited by Jasonoff; 11-28-2017 at 06:43 PM.
#40
MBWorld Fanatic!
if you flick/spin the pulleys with your finger and they spin freely with inertia (they keep going for a second after you've flicked your finger off) then they are definitely toast.
however yes, a healthy pulley will spin freely and silently, but it won't continue to spin after you take your finger off it.
#41
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2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
If yours spin easily by finger, they’re cooked.
#42
MBWorld Fanatic!
Yeah my bad, context error on my part. Spinning with no resistance means all the grease is gone.
Edit: here's a good vid. The one that spins like a Rollerblade wheel is the bad one.
Edit: here's a good vid. The one that spins like a Rollerblade wheel is the bad one.
Last edited by Jasonoff; 11-28-2017 at 06:40 PM.
#43
MBWorld Fanatic!
I know it doesn't make sense, as the alternator pulley is still fine, but I don't know what else to say about it really. I wonder if anybody else with a failed set of pulleys might notice this....of course I realise that not everybody looks at their battery voltage often too.
#45
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a unicorn tuned p30 e63
Strange as it seems (and I'm sure I might get some flack for this) but I've been monitoring my battery charging with the engine running and I'm happy to report that it's now a stable 14.5-14.6V
I know it doesn't make sense, as the alternator pulley is still fine, but I don't know what else to say about it really. I wonder if anybody else with a failed set of pulleys might notice this....of course I realise that not everybody looks at their battery voltage often too.
I know it doesn't make sense, as the alternator pulley is still fine, but I don't know what else to say about it really. I wonder if anybody else with a failed set of pulleys might notice this....of course I realise that not everybody looks at their battery voltage often too.
#46
MBWorld Fanatic!
Guess I should have actually checked ALL my idler pulleys lol. The tensioner pulley is like new, the two under the PS reservoir are not bad (not amazing but still have lots of life), and the smaller grooved one by the timing case is ok.
But... the one beside the AC compressor pulley is toast.
But... the one beside the AC compressor pulley is toast.
#47
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2005 C55 AMG
Did you ever figure out why the coolant was so low? Mine did the exact same thing. I just happened to be taking it to my mechanic when it got a coolant low message at start up. I checked the overflow tank and it was below the low line. I drove 18 miles without issue, then the battery warning message popped up and lost power steering. I limped it about a 1/4 mile to the shop. My mechanic told me belt was toast, idler pulley melted, took out the water pump as well. I told him to give it a good once over after repair, and he said that should be about all that it needs. I didn't think anything of the coolant low indication, until you mentioned it. Perhaps, it is a early sign of belt/pulley failure that we should be aware of. Had i known to check the serpentine belt after a coolant low warning, I may have prevented the water pump from being replaced. Hopefully, that is the extent of damage caused by me limping it to the shop.