April 29th I had installed: 15% Craven pulley, new NAPA 060539 belt, NGK BKR7EQUP plugs, Madness CAI & cowl mod, and oil change. Ran great for about 250 miles. Then this past thursday May 8. I started the engine, the belt was squeaking . The noise stopped when car warmed up. Drove car again friday, same thing. I've read posts here regarding the same issue. I am not mechanical. From what I can tell from reading here it is A: wrong size belt, B: belt tensioner failure, C: pulley not right and belt is off track. How can I tell which if these things it is? And, can someone explain the "holes" / belt tensioner? Or better yet a photo? Can any or all of this be determined without dismanteling anything? The mechanic is about 2 hours drive away. I'm concerned about driving that far . What are your thoughts about that distance drive? My car is an 02 MCS just shy of 70,000 miles. Please HELP!

 

I have the same problem. when it rains the belt will make noise for a bit too. My tensioner is good. I have a 15% pulley on stock belt. I AM AWARE that this isnt the best belt to run but i have 20K on it. I have taken trips as far as 5 hours with no problems. I wouldnt worry too much about it but it isnt the ideal belt. i have been told to run the NAPA belt 535, which will cut down on slipping and should eliminate the squeel we have but i just havent gotten around to it yet. I will eventually but right now i have bigger things on my plate. my R53 is curently at the body shope getting the JCW spoiler put on. possibly after that.

 

What about the possiblity of it being the tensioner?

 

i guess its possible, ive never had a bad tensioner so i wouldnt know. I was just giving info that i had available. If it is a bad tensioner then its the bearings and it will get ALOT worse over time. thats about all i got sorry

 

Are there marks on the belt. when my belt tensioner went bad It had marks about every inch or so. It looks like the the texture of the belt has been taken off and the belt is worn smooth.

 

Well, I figured out the "hole" thing on the tensioner and it has 1/2 hole showing. I guess that's okay. The belt seems to be lined up with everything - at least as near as I can tell. It also drives okay. The tensioner itself doesn't show any oil/fluid on the damper/shock. I started it again, still squeals for a short time. My husband applied belt dressing. I guess tomorrow I'll see if there is any change at start up. Still, any imput from out there in NAM world would be greatly appreciated!

 

check the belt on the idler pulley. when my MCS was making the squeaking sound, the belt was about a rib off of the idler pulley (towards the passenger side on a LHD mini)

 

change the belt asap. the 539 belt is simply too big. I've run the stocker, 539, and 535 on my 15% pully so I've got quite a bit of experience on the situation. If the belt is slipping it is being shreded... if it breaks the tensioner will crash into the crank pully and thus destroy it. You will then have a car that doesn't go any where, a $1000 bill from a dealership to replace and install the crank pully and put on a new tensioner while they are in there and a whole lot of headache.

Chances are at 70k and that age your tensioner is close to the end of it's life. Your diagnosis of what is potentially wrong is spot on. I would get the belt swapped to an 535 immediatly and that will give you a quick partial fix on the situation. I would then start planning when you can replace your tensioner mechanism and add a tensioner stop to it (20 bux for the stop) Should your belt ever break at that point the tensioner will not crash into the crank pully.

I know this seems excessive but i've had to deal with friends cars that have snapped belts multiple times. The tensioner mechanism on this car is a horrible design plain and simple. I am very **** about the situation... but i'm currently in the rhythm of replacing my 535 belt every 10k.... call it excessive but if you're interested enough in performance to add a pully... you should be very interested in the condition of your belt. Your belt slipping alone will nock 15-20hp off your car and cause havok with your air fuel ratios... Putting your car in dangerous positions at certain driving situations.

 

auto zone gatorback 4060537

 

Ok, I'm pretty nervous now after reading - maybe too much - NAM. I've ordered a new belt tensioner, DT tensioner stop, and the shorter belt (thank you Way!). As soon as they arrive it's back to Illinois to get it all installed. Hopefully that will solve the problem. I'll certainly have more peace of mind with the new tensioner after all this reading. My car turned 70,000 miles yesterday.

ALSO:

How can one tell if the pulley is not installed correctly? Since that also seems to be an option in the mix of possible noise makers it would be very helpful to be able to check for some clue there. It's quite nerve wracking to drive a car that is not quite right two hours for service wondering if I'll arrive in one piece.

 

I hope I didn't overly scare you. I've just had some bad experiences with my belt tensioner/belt and I was hoping to save some one the headache. (by suggesting they be proactive)

at any rate good move picking that stuff up... once you get all that installed you'll be able to drive the car at 110% without a care in the world.

As far as checking the pully there aren't that many options. The only real way that I know of is checking it by sight. When the belt is on make sure that all the V's of the belt sit comfortably on the pully. Start the car up and watch the belt spin... It should spin without much if any side to side movment on the pully. That's about all you can do. If it's not on right it will slowly start to shred belts and as long as you check your belt every time you fill up for gas (every other is fine) for the first 3-5k miles your pully is on there... you're g2g.

Just as an fyi with a 535 I see 1 hole with the tensioner and a little bit of the spring guide leading up to the second. Once the belt is worn in and has stretched I can still clearly see one full hole.

Just relax and take things slow at first, you're on the right track, you're doing what needs to be done to be able to have a trouble free modded car. It just takes a bit more then some might suggest.

 

Thank you for the reassurance. Since I am not mechanically inclined this glitch has made me more than a bit nervous. Reading NAM is both a blessing and a curse. I get to find out all the possible problems. Hopefully I'm just overthinking the issue. For now I'll not drive CHEQQRS until I can head down to Illinois with the new parts in hand. I'll try not to think about the other possibilites. Especially since my OEM pulley was one of those that wouldn't come off. The mechanic had to cut it to pull it off. At least I know he is quite **** and was very careful cutting it. I just hope the pulling hasn't messed up the supercharger.

 

crap, my belt squeals every time from a cold start and it's driving me nuts! i'm on my 2nd JCW belt now (1st one was put together with the M7 16%). for about 2 weeks with the new belt, i was enjoying squeal-free cold starts but it eventually squealed again

a fellow Mini owner said that the squealing can possibly come from the top part (non-grooved) of the belt making contact with the tensioner pulley. if this is the case, will belt dressing help?

 

do they actually 'squeeeeeeel' ?? Hmm

 

just a heads up I just replaced my Cravenspeed 15% pulley with an Alta V.1 pulley to fix this problem. We placed the 2 pullies side by side and you could see the Cravenspeed was 1 to 2mm shorter causing the belt to rub on the outermost side of the pulley. It has been about 2k miles on the car since the pulley swap and the belt is still silent and wearing properly now. I will be sending the pulley to Cravenspeed to have them look at it.

 

update... Cravenspeed has looked at the pulley and did not find a defect with it. Kellen at Cravenspeed tried everything he could to find a problem with it but found none. As to why the Alta pulley V1.0 resolved the issue is unknown. I don't want to mess with my Mini by reinstalling the Cravenspeed pulley and diagnosing it as the mechanic who did the install is almost 400 miles away. I am sad that there was no defect found with it, as if there was a defect found I could justify all the hassle I went through.