I recently purchased an 05 MINI S with factory JCW (convertible) with 105K miles on it. It was fine except for the whistling noise that I attributed to the supercharger.

A couple weeks ago, I was driving home when the serpentine belt broke. There was a nice "pop" and then the battery light. I pulled it over and indeed the belt was missing. I had it towed to a local mechanic (non-MINI). They replaced the belt and told me it was done. I went to pick it up and lots of warning lights were on. The belt was on, but not working. So they went back to work. A week later they have replaced the idler pulley and the harmonic balancer. The pulley bearings were shot and the harmonic balancer had separated into two pieces. I got it back and it runs fine, but there is a rattle only at idle speed (see video).

Everything else seems fine. The sound completely disappears at anything but idle speed.

Does anyone know: is this the tensioner? Is it fine like this, or does the noise mean I really need to replace that as well?

 

Sounds like your timing chain to me...
May need to replace timing chain tensioner or the guides if they are worn.

Cheers

Chris

 

Thanks for the suggestion. Would that sound change with the higher idle speeds? I mean, the engine sounds great as soon as it is above idle.

 

Start with detensioning the belt and see if the noise goes away, that rules out anything in the belt drive, if the noise persists then delve deeper into diagnostic.

Many people have misinterpreted the bushings on the tensioner being failed as chain rattle. We sell Powerflex bushings for the tensioner that are a breeze to install if that is the case, or we have full replacements, all on hand.

Let us know if you are in need of any help.

 

Ah, great idea, I hadn't thought of that. I'll give it a shot and see what happens.

 

After checking various videos on the Internet, I took it to the shop to check it out. They say it's the tensioner and want $700 to fix it. I thought I'd do it myself, but the videos I have seen have you removing the tire, the engine mounts, and even the front bumper assembly! I guess I'll be saving up for a bit.

 

The part is less than $100.
https://www.amazon.com/ACDelco-38404.../dp/B001KSDZOY

If you aren't comfortable doing the work, ask them if they will install the part if you bring it in yourself. The job only takes about an hour. Hopefully they will, or if not maybe there is a more reasonable shop in your area that won't charge quite as much.

Any semi competent mechanic can do it, there is nothing to adjust and you only need a pry bar to get the belt off. The special tool is handy but definitely not required.

 

Interesting. I've worked on plenty of engines before, but the recent videos I found about working on this item show the entire front end coming off. I'll have to look around some more because if it's a simple bolt-on without having to remove a day's worth of parts, I can certainly do it...

 

Yeah there's no reason to take any of the front end off.

When I did mine I just loosened up the motor mount bolt to jack up the engine enough to wiggle it out of there.

I see there is a video where the guy takes the motor mount off completely and gets the pulley out that way. Seems like too much extra work but maybe its easier. Either way you need to support the engine from underneath.

The rest of the job is pretty self explanatory. I looked at the pelican how to but it doesn't make any sens to me.. They have you taking off the air box and other things for no apparent reason.

 

I'm a little tardy to the party, but it takes us less than an hour to replace a belt tensioner and should take any decent tech about 2 hours max, so it sounds like they may be pricing it to scare you out of the job.

The biggest bear of the job for someone who doesn't have all the tools is to detension the belt, other than that it's two 16mm bolts and two 10mm bolts on the tensioner.

If the car still has a stock crank pulley or ATI equivalent I usually just remove the upper engine mount, engine mount bracket, and remove the tensioner from the top. Obviously requires you to support the engine with a jack, but saves you the money and hassle of sourcing a crank pulley puller if you don't already have one.

 

Thanks -- with the encouragement from you two, I'm going to give it a shot myself. I'm going to have to find a belt tensioner tool, or something I can use as one, but them I'll give it the old college try!

 

Well, I managed to make a mess... No problems until the last bolt on the tensioner. I have no idea how you guys manage to take that out from above. I can barely fit my hand down the side of the engine enough to just barely touch that bolt, never mind seeing it or putting a wrench on it. I don't have a shop, so I think I'm going to have to attempt to put the mounts and things back together, then jack up the side and try and remove the tire, figure my way through the side or something because I just don't see any way to get to that last bolt from the top.

 

Having the front of the car up on jackstands and the right front wheel off will make the job easier. Once you've gotten that taken care of then you will remove the lower engine mount bolt, support the engine with a jack, and remove the upper engine support bracket. Once you've done that you should be able to access the bolts from the top and bottom.

 

Whew! I'm done and it is purring quite nicely now instead of that rattling!

Thank you all who chimed in with advice and suggestions, it was good encouragement to keep me going. I have worked on cars a lot in the past, but never had the guts to tackle the MINI.

A couple notes: you guys who pull it out the top with sockets must have small hands, small sockets, and a slightly different layout. The space on my MINI between the side of the engine and the frame is about an inch and a half. I can get my fingers in there, but not my hand. All my sockets are too large, only a wrench would work. And the assembly wouldn't come out that way, either, I ended up feeding it back towards the exhaust and around. And if I ever get to do that again, I think I'll tape up that relay or whatever it is attached to the engine mount, that thing kept cutting my arm!

Again, thank you all for the help and suggestions!

 

Awesome... glad you got it!