Noting the tensioner was replaced not too long ago, it probably drops a bit on the suspect list me thinks... Although the PowerFlex rebuild bushings are another great investment. Here's how mine went down: Had the m7 16% pulley installed when the accessory belt shredded, just convenient timing kinda' thing. Tensioner replaced under warranty at that time too as it was hosed. Installed NAPA belt recommended for 15% reduction pulley. Immediately picked up a chatter/rattle on start, especially when cool/cold out. Watched the tensioner bump around a bit, but not wildly so. Noise dissipated after running for a bit. Noting the action of the tensioner, dealership replaced it thinking maybe the new unit was defective. Same end result. Changed to tighter belt (recommended NAPA for 17% reduction pulley), thinking maybe the 15% one had too much slack. Good at first. No noise. Then as a few weeks passed, the noise came back. Acting on a whim after reviewing the shop manual one more time for suspects, I suggested replacing the idler pulley as it was a cheap part and just about the only strong possibility left. Plus when we put ears on the motor, nothing else really seemed to produce the noise (alternator, water pump, etc). Just tensioner chatter. So, we popped the idler out and found it was hosed via too much wear on the inside allowing movement (felt smooth on hand actuation though). New one installed - all good. Our theory/summary in the end was the tensioner definitely failed. Idler was on its way, but the subsequent changes to the belts with the new tensioner & SC reduction pulley provided initial tension to smooth over the worn idler movement and make the tensioner move better/smoother/quieter. Then as the belt stretched out a bit, the extra movement would allow the idler to move around and again allow the tensioner movement/noise. The noise on a cold vs. warm start was attributed to simply temperature change effecting the swelling of the belt. Ditto for running, once the belt was up to temp and the idler kinda' got its groove on, then the tensioner would move a little bit but everything seemed pretty decent. For the record, alternator failures on the MINI are rare according to the mechs here. Not impossible, but almost unheard of... Obviously your situation may be totally different, but thought I'd detail mine just to add fuel for thought.
EXCELLENT insight - thanks. I may replace my idler soon just for PM. Sounds very similar to my symptoms.
I was gonna say... that if it's the idler, remove the belt and you should feel play in it if it's bad. FWIW, I think the idler is a cheap POS... But it is what it is. GT Tuning in England makes a very stout replacment, but like all his stuff, it's not cheap to get in the US. Matt
I'm very curious to see how this turns out. I had a similar situation following my SC pulley swap, where the tensioner started bouncing around wildly with the 15% pulley and a new belt. Multiple pulleys and belts did not solve the problem Putting the original, 40K mile belt back on got things to be much quieter, but still not where it should have been. A trip to the dealer ended up with a diagnosis that the bearing dust shield on the SC was now worn, which necessitated a fully SC change (can't replace the dust shield or bearings, I guess). My '05 SC was replaced with an '04, 15% pulley already in place, and I've now gone 57K more miles with that set up. Until recently, I was the only person I had ever heard up who needed to replace a SC following a pulley swap. Told the story to one of the guys from the pulley manufacturer at a local show last year, and his reaction was, "Oh yeah... I heard about this one. That was you, huh?" One of our local club members just had the same thing happen to her car (an '03) following her pulley swap. I've still got my original SC, hoping to get it rebuilt one of these days.
You can get SCs rebuilt by several firms now. Used to be that wasn't the case. I'm sure MINI would say you have to buy a gold plated brand new unit at a cost of 42 gazillion dollars or the world would end.... Or something like that. Matt
Actually, the guy I worked with at MINI (don't remember if he was the service manager or just a grunt) went to bat for me in a BIG way, and found someone locally that was willing to sell his SC for $200, rather than the $2K or more that a new one would have cost.
Mine is running quite smoothly and quietly at the moment. Newest tensioner and belt seem to do it. But I'm going to replace the idler anyway.
Yeah - actually considered the GT Tuning idler when mine was dead, just too hard to afford & get across the pond. May do it on my "new" R53 when it comes time...
Haven't looked recently, but previously - no. Had to do the whole exchange rate purchase and ship across the big pond to get it...
Update - found the root cause - idler bearings were shot. spins freely, but also has lots of play side-to-side. 10 minute job to install the new one - easy. Done. Will add this to my PM list for every 50K miles, unless I break down and get the GTT one.
Hmmm seems like GT Tunings site is down now. I think it's 67 pounds for the part, and 14 for shipping.... That's like what, $127+? I'm thinkin' in might be good idea to make one on this side of the pond.... Hang tight! Matt
I volunteer to be your first customer. (I'll also be getting some beehives). GTT isn't thought of too highly on MiniTorque. Not sure of the reasons other than their over-rated tuning packages. Back OT, glad you found the culprit.
Possibly.. but I like what they do. I'm not on the foreign boards enough to understand thier soap operas. The ones over hear are enough to deal with! I loved the testing that they did on exhaust backpressure 3 years ago or so. They have good parts, and up till recently had the only intake with an airhorn to aid flow.... There would be a bunch of thier parts on my car, but the exchange and shipping makes them close to unobtanium! Matt
I have their unobtainium strut bar... It's magically delicious! I would definitely be in the market for a properly priced, well made idler pulley...
Just a suggestion before discarding an idler pulley. The pulley's sealed bearing is secured with a thin washer of sorts. Over time, or perhaps it wasn't tightened well from the factory, it will loosen causing the wiggle effect. Try an eighth turn on the bolt, if it moves easy, go for hand tight snug. The washer deforms a little when tightened and my be a contributing factor, any way, if the idler isn't gritty or noisy when turned, but it can rock, try tightening again.
Just screwing around... with some 3D modelling SW..... This is probably to much to machine, but looks cool! Matt
Sure! I'm print out a glossy, and you can have your rendering of FES Vaporware in a couple days via USPS Priority Mail! It'll be 5.5 x 8.5. FWIW, I didn't even dimension the thing when I whipped it up! I've been using SolidWorks for doing cool 3D modelling stuff, and it's totally bitchen! That took all of 3 minutes to do. Matt