timing chain tensioner's got me feeling...tense?
 

So I was wondering, with all the developments (or maybe lack thereof) with the problem of our slack timing chains and failing tensioners...is it worth swinging by the dealer to ask if they'll listen to my engine and assess whether I would need a swap? I got the timing chain and tensioner replaced right after I bought the car used with 30k miles on it in 2011, and I honestly can't tell if I will need to have it done again soon (it's got 87k on it now). I know there's a recall going on and all, which apparently is for 07-10 minis, but my vin didn't show up on the MINIUSA website, so I'm SOL in that respect. Will the dealerships always charge a fee just to give their opinion and a brief listen to the engine bay? This cold weather just seems to amplify any squeaks and rattles that my car has going on, so I could just be paranoid. I guess I just want to know what the success rate of r56 owners like myself, just having the dealership replace the tensioner/chain on their dime, without going the "reimbursement" route for a since-blown engine. Thanks for the help guys!

Can't hurt to call them and ask. I'm sure if you've got a good relationship with the dealer, it'll be easier for them to give advice without charging you, but with how much of a black mark this timing chain issue is causing MINI, you'd probably be in luck to have them take a quick listen.

I would call MINI USA first, they will be more knowledgeable and hopefully more helpful. If they look and say you have the updated parts, you can get the longer tensioner which would take up the slack. I believe it's about $18 and easy to change. I bought one then found out ours was covered in the recall.

The problem is not with the length of the tensioner per se, rather, the slapping of the un-tensioned timing chain leading to its wear and slack. At some point, you just need to replace the chain.

RECALL situation is murky, at best.
I did get mine replaced under warranty, but had to go to 3 dealers before the last one figured out how to follow the TSB and measure the chain slack. That was with 49.5K miles on my '08 MCS.
However, going to MINUSA web site, the recall lookup tool claims:
" There are no open recalls for your vehicle. Happy defective motoring."
http://www.miniusa.com/content/miniu...rt/recall.html


a

Internally, this action campaign isn't classified as a recall, which is why no one can get their car to pull up on that site. It's something that a dealer can check by running your key, or by calling MINI USA.

Ok, they call it a 'campaign.' I wouldn't say it's murky, but the dealers don't seem consistent which is why I recommend a phone call to corporate. Dealer here had to reschedule me for a loaner car, but they were great and replaced everything for free at 95k.

Are there other people with 07 S models who aren't included in the campaign? Mini has told me I am not, even though the tensioner was already replaced under warranty because of issues years ago, and replaced with the same original part (shorter tensioner). Now there is some noise coming from the chain again, and they are telling me it isn't part of the open campaign (even though it clearly should be). Annoyed.

It shouldn't matter if it was done under warranty, if the dealer installed the same defective tensioner and not the updated one Mini should cover it because it uses the known defective part# for the tensioner.

They can do a visual inspection and tell if it the old style tensioner. That's what they did on mine. When the mechanic saw that it was the original he measured the chain backlash at 70.9 and immediately scheduled me for a complete assembly replacement. It helped that my records showed regular oil changes too. he commented on that specifically. Good luck.

They brought up the chain noise in the first place during an oil change... when I made the argument (quite clearly!) that it should be replaced on their dime, they insisted my VIN wasn't included in the recall. Corporate agreed. Kind of BS that they have an open campaign for a part for which my year/model was included, notice the problem themselves, and then say I am excluded from the campaign... they want a silly amount to do a job that would cost me $30 otherwise as well...

Try another dealer!
I had to go through 2 until the 3rd was competent and informed enough to measure the chain slack and schedule my '08 MCS for a new chain and tensioner job last summer. And that was while the car was still under warranty, and the reimbursement for the job was a sure thing for the dealer to collect from MINI USA!

Don't attribute to malice (or greed) that which can be adequately explained by stupidity and incompetence. Sadly, that holds true to 95% of the disagreements I've had with my MINI dealer. :sad:

a

I replaced mine timing chain tensioner yesterday on my 07 MCS. I purchased the car a month ago with 79k, after a week or so the little rattle started. After reading all the comments I decided to replace the timing chain tensioner. The new updated tensioner caught the threads with no problem or any pressure at all required to get it started. The old tensioner felt like it was hand tied by the dealer when they replaced it at 30K. No rattle at start up, I drove the car for few mile with any issues at all. After few hours I started the car to drive to work and the rattle was there again, this time less noisy than before. When I pressed the clutch the rattle is less noticeable or nothing at all.
Anybody have any ideas??

If your replacement tensioner fitted easily with no effort at all to start it in the threads, then your chain is already worn and stretched past the limit that it needs replacing. Fitting a new tensioner of the same length on a chain still in spec requires some effort to overcome the spring tension of the plunger against the chain guide. That's why it still rattles with the new tensioner fitted, I replaced mine a while back as it would intermittently rattle for a second on cold starts, and I think due to the extended oil change regime, and very tight machine tolerance in the tensioner, it would stick, new tensioner has cured that, but it took some effort in the confined space at the rear of the engine to start it in the thread's, I think my chain is therefore still at a serviceable length.

I agree, if the rattle is already there your timing chain is already stretched and needs replacing soon!

Fingers crossed that early oil changes will keep the rattle away.

If I'm reading this correct, oil changes don't effect this at all. It's the timing chain, which the only thing that will prevent it from slapping is a tensioner and the correct length

Extended oil service intervals will indeed affect this issue, the tensioner does get gummed up with residue and debris and sticks, this then allows the chain to operate without the coreect tension, slaps around and stretches beyond it's serviceable limit ....regular oil changes and treating the tensioner as a serviceable item and change it at around 40 to 50k will in my mind solve this issue.

I will add that the action of the tensioner I replaced was noticeably not as smooth as the new item, spring tension and length of tensioner was exactly the same, but the original was sticky and I had a very intermittent rattle on cold start if the car had been left to stand for a day or two, therefore I would put it down to debris build up in the tensioner which is known to be machined with very tight tolerances. For the price of a new tensioner £25 or about $40 I guess, its a no brainer to change it and do yearly oil changes instead of the mini long term ones.

Thanks everyone for the good information. I will try to schedule the timing chain replacement this week.
Anybody have any idea on how much I should be looking to spend on this repair?

If you are under warranty - nothing.
If out of warranty, I've heard quotes of dealer between $1800-$2200.

You are near Atlanta, the home of Waymotorworks.com - a competent independent. Give them a call, I'm sure they will do a better job than a dealer, for less money.

Good luck,
a

I tend to think all the instances of people who followed short oil change intervals yet still had timing chain issues is a good indication that shortening the interval has no bearing on the likelihood of failure.

I would agree that the oil change intervals do not affect the behaviour. The problem is not the tensioner, but the chain itself. The same problem is also present on BMW's N47 diesel engine. However to change the timing chain on that car you actually need to remove the engine, so the situation is much more complicated and costly.

I think the key issue here is the design: put too much tension and you wear or break the plastic guides. Too little and it will vibrate, eventually breaking the guides again (which is BMW tells you to use the shorter tensioner if you put a new chain in). So there is a very small margin to get it right, but then you need to factor in wear over the lifespan of the engine, so it does get complicated or impossible.

Slack chain whipping around breaks the guides, not over tensioned chain, there is nothing wrong with the chain itself, but the way its tensioned, hence.the revised tensioners, one that included a spring that was not in the original.

The original tensioner is spring loaded as the replacement ones. I have my original one next to me... There is nothing wrong with it, it was just shorter than the replacement part. If yours didn't have spring action, maybe it was because the spring failed.

The oil allowed in the tensioner is just for damping. The holes are too small to allow pressure driving of the rod. I have seen hydraulically-actuated tensioners, but those are very different.

I didnt use the right word's, I meant there was a different spring in the revised tensioners, a stronger version than the original to assist keeping the chain under tension.

Also chains have been used for a hell of a long time in many applications without issues to control cam drives, if its lubricated and tensioned correctly it WILL last the lifetime of the engine, this is the point where the mini system fails, tensioning..... its not the chain that's the issue.