Fixed! Update on Post #46.

Hey all, I just bought an '04 MCS and there is a fairly loud grinding rattling sound around the belt area. It almost sounds like when a bearing goes out in a pulley and the sound is tied in with the rpm, being that as the rpm's increase so does the speed of the noise. You can hear it a bit at idle but you can really hear it when driving and going WOT, especially next to a wall or curb.

I'm fairly certain it's not the supercharger since when I placed a stethoscope on the SC all sounded fine. I crawled under the car and had someone rev the engine and I can hear the sound but it just bounces around and I can't pinpoint it.

I've read that the stock crank pulleys like to disintegrate on these cars so I'm kind of leaning toward that being the problem but I'd like to know what others think.

Here is a video that I found on Youtube (THIS IS NOT MY VIDEO BUT IT SOUNDS JUST LIKE THIS). Fast forward to 1 minute and you will hear the sound. Anyone have any ideas? I dont want to drop $350 on an ATI pulley without knowing it will fix my issue.

Thanks!

 

IMO sounds like the idler pulley.

 

That was on my list as well. When the idler goes bad is it known to make that bad bearing sound? I guess that would be a cheaper fix to try before the crank pulley.

Thanks for your input, I'll research some more on it. I'm guessing there is not better aftermarket idler pulley, just stock?

Anyone else have any input?

 

Yes and when it finally gives you wont be able to drive for more then about 30 seconds and your MINI will go into limp mode.
There are some aftermarket ones, but really not any cheaper then an OEM one.

 

Yeah, there is one from WMW for $38. I just didn't know if there was a better aftermarket choice available with better bearings. I'm now leaning toward it as the problem. I'll go with that before I buy the ATI and hopefully that is the issue and saves me from spending $400 on a crank pulley.

Thanks for the help!

 

Good luck, keep us posted.

 

Mine was making a similar sound until I put a new belt tensioner assembly on. The crank pulleys on the early Mini's seem to last a little longer than on the 05 and on , they were made better. They still seem to come apart but not nearly as frequent as 05-06 cranks.

 

Good info, thanks. I'm still leaning toward it being the idler pulley though because I put a stethoscope on the tensioner and it sounded fine. I'll definitely keep it in mind though. Thanks!

 

had the same problem before. it was my bushing in the small shock absorber in the belt tensioner.

 

Hmm, so that's two for the tensioner. I think I'll pull the passenger liner and get better access to the tensioner and put the stethoscope on the shock absorber portion and around that area. When I did it from above though I didn't hear anything unusual. Maybe I can put it on the center bolt on the idler pulley too to try to confirm it.

BTW, the hole on my tensioner is fully visible and then some so it's at least still tensioning the belt properly. Is the shock absorber available separately? I'm assuming no.

 

the shock absorber is not available separately (you have to buy the whole thing) you can check the bushing there by just trying to move the shock. the shock should not move or should not have any play. Try to remove the belt and try to spin all the pulleys that you see. if they are all smooth and not moving (read it somewhere sometimes it is the idler pulley) i think the belt tensioner is the culprit

 

Good idea on removing the belt and checking each pulley. I'm ordering the tensioner tool today so I'll just get the idler pulley too (it's only $38) and check the shock while the belt is off. Thanks!

 

Quick update on this. I replaced the idler pulley today and the sound is still there. Sucks too because the stock one was shot, I could wiggle it around so I thought for sure that was the problem.

Being that I thought I found the problem I didn't bother to check the other pulleys or the tensioner shock. I will pull it back apart this weekend and check it all out. I'm hoping it's the tensioner since that is the least expensive of what is left.

I'll post an update after the weekend if I find anything.

 

that is the tensioner i think good luck

 

I'm not against it possibly being the tensioner but I really don't think it is. The strut doesn't move and when I put a stethoscope on it it didn't make the rattle sound (although this was only revving while stationary so the sound wasn't as pronounced).

Has anyone ever heard this rattling sound from the crank pulley? I had it all apart again this weekend and I noticed I could wiggle the crank pulley slightly. I'm sure it's on it's last leg but I'm not sure if that is the source of the noise or not.

 

Maybe the rattle is coming from your idler pulley and not the crank pulley.

 

I changed the idler pulley last week and the noise is still there

 

I have an 04 with noise in the same area. Was the pulley on the tensioner. But while it was apart, it got a new idler pully, belt and 15% supercharger pully. Actually more, but "while we're in there" got a little out of hand.

 

Haha, yeah I know how "while we're in there" goes. Thanks for the reply. Maybe I'll just get the crank pulley and the tensioner and *hopefully* be done with it all. Did the tensioner pulley have play in it? And how was the spring on it? Mine is tight and the sight hole is fully visible and then some.

 

As far as the Crank Pulley goes, they normally won't make noise & if they do, they're "gone", remember what goes bad with the Crank pulley is the rubber between the two metal surfaces, any metal-on-metal the rubber would have to be gone or allowing the pulley portion to move enough that it is scraping on the timing cover, so when you have it apart look at the timing cover best you can, behind the pulley for signs of contact.

 

Yeah, from the little bit that I was able to wiggle it it didn't seem like it would be the culprit but I definitely do need a new one. I'm just hesitant to lean toward it being the tensioner because it seems to be in such great shape.

 

Just a though, is it possible to just replace the pulley on the tensioner? From a quick search it looks like the pulley is sold separately LINK

 

I hate to say this but also double check your S/C front & rear, here's why I say this, "normally" an idler or tensioner will not be effected by load as much as rpm, as where a Crank Pulkey & S/C load will play a bigger part as far as movement or lack of. I know that when my W/P gears were starting to go, it sounded like it could have been coming from the front simply because the sound of the rattle was transfering through to the front shaft.

Good Luck.

 

Thanks for the thoughts. I do plan on taking the SC off and replacing the water pump and oil. Crossing my fingers that isn't the issue.

 

In that case you may get lucky if it just started, remember most if not all W/P gear failures are related to lack of lubrication caused by the oil seeping into the S/C, so if this were to turn out to be the noise, minimal damage may have been done & an oil refill may just prolong the life of everything back there. And overall "just couldn't hurt".