Have a slight rattling noise coming from the engine bay (passanger side). It is very low and sounds like a loose idler pulley (bad ball bearing)confused: . It is there when the car idles, it goes away when the revs go up. I have a 2005 Cooper. Wonder if any1 else has had a similar problem.

 

My 03 MC had a bad bearing in the idler pulley at 23,000 miles.

 

Does it go away when you push the clutch in? Some throw out bearings chatter a little bit with no load on them.

 

On my 03, replacing the pulley stopped the problem completely

 

It is not affected by engaging the clutch. It comes on after about 20-30 minutes of city driving. I am pretty sure it is the idler pulley, but I hope I would not have to replace the whole tensioner.

 

So do you think the issue is the tensioner pulley or the idler pulley? The only non-OEM replacement for these that I have seen is GTTuning. I have both and they are works of art, but they are pricey. OEM may be a cheaper choice.

 

I believe it is the idler pulley since I put a stethoscope and it sounded louder than the tensioner pulley. However not 100% sure. I was looking at the GTT stuff and I would rather bite the bullet and buy their twin bearing pulley. I know they make great quality products and it will probably last longer. I guess I will find out if that fixes the problem when I get my pulley installed!

 

While I had mine apart, I went ahead and did the crank pulley and the tensioner stop too. I have been very happy with the combination.

 

To check idler pulley health, take tension off the belt, grab the pulley and wiggle, if it moves, torque the bolt (sorry I don’t have the spec with me but it’s in the Bentley and it’s not much 35 ft-lbs? because it fastened to the thin camshaft chain cover) and try to get movement. Mine (MCS) required re-torque at fairly low mileage and has not loosened since. If it has rocking movement and tightening does not stop it, then replace the pulley.

The same diagnostic procedure is valid for the tensioner pulley. Most tensioner failures are because the damper failed (MCS), or cracks formed due to overextending the tensioner arm contacting the engine mount bolt that protrudes directly above the mid point in the arm’s arc (MCS), or the bearing bolt had loosened allowing it to operate in an unstable state (valid for both arm bolt and pulley on the MC).

 

thank you for all your replies . I will attempt to fix the problem after the holidays.

 

My idler pulley started making noise a few days ago, and yesterday it just crapped out on a drive up to vermont and shredded my belt. Had it towed 20 miles to my parent's place, and now i'm waiting for a belt and pulley to be UPSed to me because the mini dealer doesn't have them in stock. I'd fix the pulley before it goes on you.

 

just incase this is not it. if you have a pulley, check to make sure it's tight. i had a car come in a month ago that sounded like a bad bearing, but it ended up being the supercharger pulley bolts where not tight and the pulley had loosened up. since i had not installed this i had no idea what was done, but we jacked up the motor and took it off and replaced it with a new pulley since it worn down. so far no other problems, but it sounded just like a bad bearing. good luck

chad
detroit tuned

 

I took a better look wierd thing is that the harmonic balancer's bolt looked like moving. However the balancer itself did not have any singns of movement. Mayb needs to be retightened. I used a stethoscope and one of the tensioner pullies deffinetly sounded noisyer than normal. Mini said that the pulleys cannot be ordered separetaly but I have to replace the whole tensioner. Which is ok because its not that expensive. I will let you guys know if that fixes the problem .

 

How much did they say it would ( tensioner ) cost?
Check with Classic they are a vendor on this board and give NAM people a discount for the best price.

 

I am in Canada so Classic is out of the question as they are not allowed to ship directly to Canada. Mini quoted me $155 CDN. I get a special shop discount. The price is reasonable considering you get the whole tensioner assembly. Thanks for the help .

 

Bought the part. Should be able to put it in Saturday. Anyone have the torque specs for the tensioner bolts?

 

Still hearing the same noise after replacing the belt tensioner. It sounds like something is loose only comes on after the car warms up. Im gonna wait till it gets really loud so that I can have a mechanic check it.

 

i just replaced my first Idler pulley this weekend for a customer. the car had 104K on it and it was not making any noise, but after we pulled it off, the bearing had slop in the up-down motion (while on the car). there was no in out motion (again while it was on the car). this will not help your problem, but a bit of info NAM may like.

euro_tuned, where are you from?

 

I am in Toronto, Canada. I am starting to think its one of the heat shields near the headers. I can hear the rattle sometimes when going over bumps. Today no sign of it . Like I said I will wait till it gets loud and take that puppy apart. The way I see it the tensioner wasn't a waste of time since it was louder so at some point I would have ended up replacing it.

 

your not to far away from me. you could always drive on down and spend a few hours at the shop. find the rattle, get some mods, have some fun.