*STOCK C32 / M112K owners: Check your OE Idler pulley!!!*
11-18-2008, 07:23 AM
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11-18-2008, 06:38 PM
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2008 A8L, 2002 996TT X50, 2009 X5
boohooramblers - excellent information (as always); thanks for taking the time to enrich the knowledge-base available here on MBW. 
11-18-2008, 10:25 PM
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07 E550, 02 C32, 91 300E
Yeah well I figured if it screwed with the tensioning, it could screw up the air pump and give an emissions related error code. I've never heard of advance auto, but I looked them up and they're mainly east coast/midwest only with nothing out here. I've got an extended warranty anyways so I'll just hit the dealer.
11-19-2008, 12:26 PM
#30
Here's a replacement alternative to your stock size idler pulley (smooth one below the SC).
Click the link below and scroll down to P/N's MTB460089 & MTB460089B toward the bottom of the page. These are DOUBLE bearing pulleys and aren't pricey at all. Our cars use a 90mm idler stock and will fit w/out modification (other than a longer bolt). There is also a 100mm version of this. If you're running the Gatorback belt with the Code3, your belt is too long to give sufficient tension; the 100mm should remedy this. Also, I'm not sure if this will fit on the belt tensioner, but that pulley is the same as the stock idler, so it might be a good idea to replace that at the same time. This will not replace the idler pulley that came with your larger crank pulley since this is too big.
http://www.rpmoutlet.com/03cobraasp.htm#2
There are numerous other 90mm pulleys available from other vendors as well, since this is a very popular and necessary upgrade for the Cobra guys. They are available in many different colors but these are the only double bearing versions I've seen.
Click the link below and scroll down to P/N's MTB460089 & MTB460089B toward the bottom of the page. These are DOUBLE bearing pulleys and aren't pricey at all. Our cars use a 90mm idler stock and will fit w/out modification (other than a longer bolt). There is also a 100mm version of this. If you're running the Gatorback belt with the Code3, your belt is too long to give sufficient tension; the 100mm should remedy this. Also, I'm not sure if this will fit on the belt tensioner, but that pulley is the same as the stock idler, so it might be a good idea to replace that at the same time. This will not replace the idler pulley that came with your larger crank pulley since this is too big.
http://www.rpmoutlet.com/03cobraasp.htm#2
There are numerous other 90mm pulleys available from other vendors as well, since this is a very popular and necessary upgrade for the Cobra guys. They are available in many different colors but these are the only double bearing versions I've seen.
NICE!!! Thanks for sharing. Whats the advantage to the "double bearing."
Just out of interest, I called my service guy at the local MB dealer. I gave him my vin and he said that the 04s did not have this "guide pulley" (his term) problem and that my car and most 04s were NOT part of that campaign. I guess if you have an 02-03, you can call the local dealer, give em your vin and they can check on the MB STAR for you to see if any of the pulley issues are related to your particular car. I am glad I did.
Last edited by Newzchspy; 11-19-2008 at 03:21 PM.
11-19-2008, 03:48 PM
#31
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2002 C32 1987 190E 2.3 334K miles and going
Here's a replacement alternative to your stock size idler pulley (smooth one below the SC).
Click the link below and scroll down to P/N's MTB460089 & MTB460089B toward the bottom of the page. These are DOUBLE bearing pulleys and aren't pricey at all. Our cars use a 90mm idler stock and will fit w/out modification (other than a longer bolt). There is also a 100mm version of this. If you're running the Gatorback belt with the Code3, your belt is too long to give sufficient tension; the 100mm should remedy this. Also, I'm not sure if this will fit on the belt tensioner, but that pulley is the same as the stock idler, so it might be a good idea to replace that at the same time. This will not replace the idler pulley that came with your larger crank pulley since this is too big.
http://www.rpmoutlet.com/03cobraasp.htm#2
There are numerous other 90mm pulleys available from other vendors as well, since this is a very popular and necessary upgrade for the Cobra guys. They are available in many different colors but these are the only double bearing versions I've seen.
Click the link below and scroll down to P/N's MTB460089 & MTB460089B toward the bottom of the page. These are DOUBLE bearing pulleys and aren't pricey at all. Our cars use a 90mm idler stock and will fit w/out modification (other than a longer bolt). There is also a 100mm version of this. If you're running the Gatorback belt with the Code3, your belt is too long to give sufficient tension; the 100mm should remedy this. Also, I'm not sure if this will fit on the belt tensioner, but that pulley is the same as the stock idler, so it might be a good idea to replace that at the same time. This will not replace the idler pulley that came with your larger crank pulley since this is too big.
http://www.rpmoutlet.com/03cobraasp.htm#2
There are numerous other 90mm pulleys available from other vendors as well, since this is a very popular and necessary upgrade for the Cobra guys. They are available in many different colors but these are the only double bearing versions I've seen.
I don't have any other mod except for the C3 pulley.
11-19-2008, 03:58 PM
#32
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Checking for abnormal pulley sounds: Obviously I visually checked and put my ear up against all the pulleys; however, I wasn’t able to hear anything of note. That’s where the stethoscope / piece of rubber tubing is of use. With the engine running, place the piece of tubing very close to the pulley and you will be able to hear any abnormal sounds (please be careful doing this!). For my idler pulley, there was a nasty raspy sound coming from the pulley – most likely an early bearing problem.
I have noticed it seems to come and go. When I have come off an extended freeway or hard drive, it is there. When the car idles for a minute or two, the sound will often fade away. It sounds like a bad bearing to me. I wonder if the idler pulley gets worse at warmest temps.
11-19-2008, 07:02 PM
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2002 C32 AMG
Are you saying right now my stock belt is too long because of the C3 pulley and using a 100mm idler pulley will compensate the slack or lack of tension. Also, what do you mean by 'this will not replace the idler pulley'
I don't have any other mod except for the C3 pulley.
I don't have any other mod except for the C3 pulley.
What I was actually saying is that this pulley will not replace the idler pulley that came with your larger crank pulley. The overdrive crank pulley kits all come with smaller (than stock) idler pulleys. If you have an overdrive crank pulley, neither the 90mm or 100mm pulleys will fit without a using much longer belt. The 90mm pulleys (which are the same size as stock) will only work w/ a setup using the stock crank pulley.
11-19-2008, 07:14 PM
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2002 C32 1987 190E 2.3 334K miles and going
If you're using the stock belt you should still be okay. If you are using the Gatorback w/ Code3, your tensioner is most likely not putting enough tension on the belt. The Gatorback is NOT the same size as stock. It's about a half inch longer. Obviously, the Gatorback belts are available in many different sizes, but the belt that usually "works" on our cars is actually a little longer than the stock belt. In fact, Good Year does not even have an aplication for our cars listed in the Gatorback catalog.
What I was actually saying is that this pulley will not replace the idler pulley that came with your larger crank pulley. The overdrive crank pulley kits all come with smaller (than stock) idler pulleys. If you have an overdrive crank pulley, neither the 90mm or 100mm pulleys will fit without a using much longer belt. The 90mm pulleys (which are the same size as stock) will only work w/ a setup using the stock crank pulley.
What I was actually saying is that this pulley will not replace the idler pulley that came with your larger crank pulley. The overdrive crank pulley kits all come with smaller (than stock) idler pulleys. If you have an overdrive crank pulley, neither the 90mm or 100mm pulleys will fit without a using much longer belt. The 90mm pulleys (which are the same size as stock) will only work w/ a setup using the stock crank pulley.
11-19-2008, 09:26 PM
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2002 C32 AMG
[/B]
NICE!!! Thanks for sharing. Whats the advantage to the "double bearing."
Just out of interest, I called my service guy at the local MB dealer. I gave him my vin and he said that the 04s did not have this "guide pulley" (his term) problem and that my car and most 04s were NOT part of that campaign. I guess if you have an 02-03, you can call the local dealer, give em your vin and they can check on the MB STAR for you to see if any of the pulley issues are related to your particular car. I am glad I did.
NICE!!! Thanks for sharing. Whats the advantage to the "double bearing."
Just out of interest, I called my service guy at the local MB dealer. I gave him my vin and he said that the 04s did not have this "guide pulley" (his term) problem and that my car and most 04s were NOT part of that campaign. I guess if you have an 02-03, you can call the local dealer, give em your vin and they can check on the MB STAR for you to see if any of the pulley issues are related to your particular car. I am glad I did.
Last edited by Eleventeen; 11-19-2008 at 09:30 PM.
11-20-2008, 12:26 AM
#36
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OK, I went out today and purchased a mechanic's stethoscope (only $3 at Harbor Freight) and checked the sound of the idler pulley. I did not hear anything abnormal. Since I was in a parking lot on my lunch hour, I will give a good listen to it and the other pullies tonight, because I definitly have a strange sound coming from under my hood.
I have noticed it seems to come and go. When I have come off an extended freeway or hard drive, it is there. When the car idles for a minute or two, the sound will often fade away. It sounds like a bad bearing to me. I wonder if the idler pulley gets worse at warmest temps.
I have noticed it seems to come and go. When I have come off an extended freeway or hard drive, it is there. When the car idles for a minute or two, the sound will often fade away. It sounds like a bad bearing to me. I wonder if the idler pulley gets worse at warmest temps.
It is entirely possible that the sound you are hearing from the cabin is not the idler pulley then. I would say that if the idler bearing is failing, you should be able to hear an abnormal sound using the stethoscope (relative to the other pulleys) - even if the sound comes and goes from within the cabin.
11-20-2008, 08:58 AM
#37
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How did your test go this evening? Did you listen to the other pulleys in addition to the idler?
It is entirely possible that the sound you are hearing from the cabin is not the idler pulley then. I would say that if the idler bearing is failing, you should be able to hear an abnormal sound using the stethoscope (relative to the other pulleys) - even if the sound comes and goes from within the cabin.
It is entirely possible that the sound you are hearing from the cabin is not the idler pulley then. I would say that if the idler bearing is failing, you should be able to hear an abnormal sound using the stethoscope (relative to the other pulleys) - even if the sound comes and goes from within the cabin.
11-24-2008, 09:30 AM
#38
Super Moderator Alumni
How did your test go this evening? Did you listen to the other pulleys in addition to the idler?
It is entirely possible that the sound you are hearing from the cabin is not the idler pulley then. I would say that if the idler bearing is failing, you should be able to hear an abnormal sound using the stethoscope (relative to the other pulleys) - even if the sound comes and goes from within the cabin.
It is entirely possible that the sound you are hearing from the cabin is not the idler pulley then. I would say that if the idler bearing is failing, you should be able to hear an abnormal sound using the stethoscope (relative to the other pulleys) - even if the sound comes and goes from within the cabin.
As the car was idling, I was not getting the sound that I have heard when driving for extended runs. It sounded very normal to the naked ear. When I placed the stethoscope on the idler, I noticed it seemed to vibrate where the other pullies were very steady. Once I got the tip of the scope on the idler, it did seem a tad "grindy" sounding. Again, I do not know if what I was hearing was normal or out of norm. Nor do I know if the movement was out of line also.
Any feedback before I go spend money on an professional opinion?
11-24-2008, 10:22 AM
#39
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I finally carved out some time this weekend, to scope the pullies. Not being much of a pulley sound expert, I was a bit baffled. I am now thinking that the idler pulley may be going bad after all.
As the car was idling, I was not getting the sound that I have heard when driving for extended runs. It sounded very normal to the naked ear. When I placed the stethoscope on the idler, I noticed it seemed to vibrate where the other pullies were very steady. Once I got the tip of the scope on the idler, it did seem a tad "grindy" sounding. Again, I do not know if what I was hearing was normal or out of norm. Nor do I know if the movement was out of line also.
Any feedback before I go spend money on an professional opinion?
As the car was idling, I was not getting the sound that I have heard when driving for extended runs. It sounded very normal to the naked ear. When I placed the stethoscope on the idler, I noticed it seemed to vibrate where the other pullies were very steady. Once I got the tip of the scope on the idler, it did seem a tad "grindy" sounding. Again, I do not know if what I was hearing was normal or out of norm. Nor do I know if the movement was out of line also.
Any feedback before I go spend money on an professional opinion?
Re: the vibration - I'm not sure how much you are noticing. If it is excessive, that may be another sign of the bearing going bad. Coincidentally, did you check the pulley bolt to make sure it's not loose?
I examined the bearing from my idler to see what the issue was. No grease! Even though the side seals looked perfect, it obviously leeched out. Suffice it to say my idler pulley was operating on borrowed time!
11-29-2008, 04:11 PM
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Crossfire SRT-6
Hey guys,
I have the code3 s/c pulley. I would like to get my belt tightened back up to stock by using a larger smooth idler in place of the 90mm smooth idler under the supercharger.
You guys mentioned the motoblue 100mm option. Has anyone actually done this, and more importantly is the bolt hole the same size?
I was just wondering if you guys had any more information on this.
Thanks
I have the code3 s/c pulley. I would like to get my belt tightened back up to stock by using a larger smooth idler in place of the 90mm smooth idler under the supercharger.
You guys mentioned the motoblue 100mm option. Has anyone actually done this, and more importantly is the bolt hole the same size?
I was just wondering if you guys had any more information on this.
Thanks
02-07-2009, 03:03 PM
#41
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Well, I finally got around to completing this little project. I kept putting the purchase of the new Idler Pulley off. Finally, thanks to one of our esteemed members here (Thanks, razormb), I got a nice deal on an upgraded pulley. I received it a couple of days ago and chose this morning (a rainy Saturday) to do this.
What should have been a 5-10 minute project turned into a 3 hour project, but not because of the complexity of the swap. No, my issue was "materials" related. I went to every auto, hardware and Sears store nearby, looking for an E10 and E12 Torx socket. Nobody knew what I was talking about. Well, 2.75 hours later, I decided to make do with standard sockets and see what came of it.
To my surprise, I learned that the E10 could be replaced by the 11/32 socket and the E12 by the 3/8 socket. Surprisingly, the metrics did not work.
Once that was figured out, it was a 1-slice of pizza job. I even never got around to getting the beer open.
Although my old bearing seemed to turn freely, it did have a feel that the seals were damaged and the ball bearings inside were noisy. I do not know if the pulley would have given out soon, but better safe than sorry. And for the price of the pulley, I'd be nuts not to have done this.
Thanks again for the great write up and video, boohoo.
It really simplified the job for a non-mechanic like me.
Last edited by ScottW911; 02-07-2009 at 03:18 PM.
02-07-2009, 03:39 PM
#42
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boohoo,
Well, I finally got around to completing this little project. I kept putting the purchase of the new Idler Pulley off. Finally, thanks to one of our esteemed members here (Thanks, razormb), I got a nice deal on an upgraded pulley. I received it a couple of days ago and chose this morning (a rainy Saturday) to do this.
What should have been a 5-10 minute project turned into a 3 hour project, but not because of the complexity of the swap. No, my issue was "materials" related. I went to every auto, hardware and Sears store nearby, looking for an E10 and E12 Torx socket. Nobody knew what I was talking about. Well, 2.75 hours later, I decided to make do with standard sockets and see what came of it.
To my surprise, I learned that the E10 could be replaced by the 11/32 socket and the E12 by the 3/8 socket. Surprisingly, the metrics did not work.
Once that was figured out, it was a 1-slice of pizza job. I even never got around to getting the beer open.
Although my old bearing seemed to turn freely, it did have a feel that the seals were damaged and the ball bearings inside were noisy. I do not know if the pulley would have given out soon, but better safe than sorry. And for the price of the pulley, I'd be nuts not to have done this.
Thanks again for the great write up and video, boohoo. It really simplified the job for a non-mechanic like me.
Well, I finally got around to completing this little project. I kept putting the purchase of the new Idler Pulley off. Finally, thanks to one of our esteemed members here (Thanks, razormb), I got a nice deal on an upgraded pulley. I received it a couple of days ago and chose this morning (a rainy Saturday) to do this.
What should have been a 5-10 minute project turned into a 3 hour project, but not because of the complexity of the swap. No, my issue was "materials" related. I went to every auto, hardware and Sears store nearby, looking for an E10 and E12 Torx socket. Nobody knew what I was talking about. Well, 2.75 hours later, I decided to make do with standard sockets and see what came of it.
To my surprise, I learned that the E10 could be replaced by the 11/32 socket and the E12 by the 3/8 socket. Surprisingly, the metrics did not work.
Once that was figured out, it was a 1-slice of pizza job. I even never got around to getting the beer open.
Although my old bearing seemed to turn freely, it did have a feel that the seals were damaged and the ball bearings inside were noisy. I do not know if the pulley would have given out soon, but better safe than sorry. And for the price of the pulley, I'd be nuts not to have done this.
Thanks again for the great write up and video, boohoo.
It really simplified the job for a non-mechanic like me.You're right - best be safe than sorry.
I hope you got to drink the beer afterwards though!
02-07-2009, 03:58 PM
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03-03-2009, 10:29 PM
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C32
Hey thank you for this write up. I checked mine and saw it was orange so replaced it. I forgot to do the spin test but the metal in the middle of the pulley was slightly thinned down... It looked like a disaster, very dirty/mud/rust.
So thanks
So thanks
03-11-2009, 01:19 AM
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2002 SLK32 AMG
Hi, I had an intermittent bearing like rattling noise coming from the front part of my engine, I listened through a hose and it seems to be isolated to the idler pulley. I am wondering if this is a good time to change pulleys to something that will give more power or just have the dealer fix the problem. I am out of warranty, so either way I will have to pay for it.
also wondering would it be ok to drive the car to the dealer? what can happen if the bearings fail or seize?
I have a 2002 slk32 with 79,000mi
also wondering would it be ok to drive the car to the dealer? what can happen if the bearings fail or seize?
I have a 2002 slk32 with 79,000mi
03-11-2009, 11:50 AM
#47
Super Moderator Alumni
Hi, I had an intermittent bearing like rattling noise coming from the front part of my engine, I listened through a hose and it seems to be isolated to the idler pulley. I am wondering if this is a good time to change pulleys to something that will give more power or just have the dealer fix the problem. I am out of warranty, so either way I will have to pay for it.
also wondering would it be ok to drive the car to the dealer? what can happen if the bearings fail or seize?
I have a 2002 slk32 with 79,000mi
also wondering would it be ok to drive the car to the dealer? what can happen if the bearings fail or seize?
I have a 2002 slk32 with 79,000mi
Driving to the dealer should be OK, as long as it is not in another state. I drove mine for months with a strange sound coming from the bearing.
Good luck.
The #9 Tensioning pulley
03-21-2009, 09:42 AM
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SLK55 AMG, E320 BlueTec, ML350, (formerly) C32 AMG, MR2 Turbo, HD-FLH-FSE, BMW R100RS, Ducati M900
Pullies
It is the value of having quick easy access to good technical DIYS write ups such as this that makes this forum special. Many thanks to Boohooranblers for taking the time to share his technical expertise with us mere mortals. I had my car in the dealership last fall for service and the tech reported that my SC pulley bearing was starting to get noisy and should be replaced soon. I asked about the cost and was told that this part was about $700.
Since I was looking at the C3P pulley anyway, I got one of those which also came with a spare bearing. That fix was easy and I got the added performance from the C3P part. However, at the time, I wondered how long those guide pulley bearings would last since they have even tougher duty than the SC pulley. I really appreciate the data.
Irish
Since I was looking at the C3P pulley anyway, I got one of those which also came with a spare bearing. That fix was easy and I got the added performance from the C3P part. However, at the time, I wondered how long those guide pulley bearings would last since they have even tougher duty than the SC pulley. I really appreciate the data.
Irish
