I'm at the tail end of my factory warranty (2010 MCS), and my dealer measured my timing chain and said it came in at 71.9mm. Since it was over the 68mm spec, they replaced the whole assembly at no charge.

The question I have now is, does that solve that problem forever for me (as long as I keep an eye on the engine oil level), or can it recur, even with the updated assemblies?

I've read some threads where people have had several chain or tensioner replacements, but I don't know if that was due to the replacements being the original defective design, or if the updated versions are still susceptible to this problem.

Thanks in advance for your perspectives!

 

They have improved the design, but there are cases where that won't make a difference. In my case I had a sudden loss of oil due to the tensioner bolt backing out. Anything like this, and since the chain assembly relies on oil pressure it will be cooked. Definitely keep an eye on your oil and keep your fingers crossed.

 

Keep the oil changed more frequently (5-7000 miles) and keep it topped up in between changes. Remember that the parts and labor are warrantied for 2 years by Mini. I can't speak for the quality of the parts themselves as I only have about a 1000 miles on them.

 

Driving the car home from the dealer I had the impression that it was running more smoothly. Not a definite difference, but just a feeling.

 

I have about 41,000 miles on the timing chain cartridge that was installed in my 2008. That was in June 2012, so I don't know what generation of the parts I got.

 

According to this RealOEM page ( http://www.realoem.com/bmw/showparts...24&hg=11&fg=25 ), the tensioner was updated on 09/2011 with a new part number. I would guess this is the cutoff date for when the cars received the updated part during their manufacture as well.

Since my car was an 01/2010 build date, I figured I had the original faulty tensioner in there.

 

Thinking about this, I do think there has been at least one change to the tensioner part itself since mine was replaced. A couple months ago I was getting an oil leak fixed and the mechanic informed me I had a leak around the tensioner. He said he could tell my tensioner was not the most recent version based on the type of washer mine had. The newer version addressed a problem they were having with them starting to leak. So I did get just the tensioner replaced. Not sure whether there were any other changes to the tensioner, especially the internal workings, that would have a bearing on the chain failures/stretching.

 

prior to getting the timing chain assembly replaced, the dealer had replaced a 'crush washer' that they said was leaking.

 

If the dealer had not replaced the oil, do yourself a favor and run and have it replaced ASAP. The worst oil analysis results I ever received from Blastone lab on any car was the one from the oil change 1K after my timing chain was replaced under warranty. The fact that MINI doesn't throw in an oil change with this job is irresponsible.

As to the lifespan of the new chain and tensioner - I've heard of people replacing new tensioners after ~25K miles as the rattle returns. I don't know if those observations were based on the old or the new/re-designed tensioner part #, but keep your ears open. Replacing the tensioner is not that hard of a DIY job, and way cheaper than swapping the entire chain out of warranty ($2K job).

a

 

I paid $70 to let them do an oil change at the same time. I considered that to be pretty reasonable. I was wondering just yesterday if the new timing chain would result in more particulate debris in the oil, kind of like breaking in a new engine. Are you saying this was the source of the poor oil analysis results?

 

My primary concern would be the metal and plastic shavings from the old chain slapping around. My oil was high on Aluminum, Chromium, Iron (4x average!), Copper, Molybdenum, Nickel, Manganese, silicon, sodium, zinc. A guy from Blackstone actually called me to to warn that I should be shopping for a new engine!

However, since it took me 1K miles before I got around to changing the oil (dealer didn't offer during chain replacement, and then life got in the way before I got to it), I can not conclusively tell whether any of the contaminants came from the job or the new chain. I assume not a lot, if any, but can't be 100% certain.

a

 

Where is the dealer located? Otto's..?

 

Mini of Baltimore.

 

My oil was changed with the timing chain, but I also changed it shortly after that. Sounded like something was wearing/breaking in on that side. I am cautiously optimistic these parts will last.