From your tag I see you also have a 99 miata. I've had 10 trouble free wonderfull years with mine and while researching the MCS to replace it, came accross these disturbing threads. Not just here, but internationally. I'm starting to lean more and more towards getting one of the new re-tractable roof Miata's.

With the economy slowing down, I do hope MINI realizes thet they're loosing potential sales here. I have the means to buy the MINI which is more expensive than the Mazda, but these unaddressed issues are really troubling to me.

 

Agreed, this seems like a reasonable deduction.

Let me play devil's advocate on one other point: Many posters report their first observation of the death rattle only after having driven a few thousand miles (admittedly the variance is large) -- rarely right out of the showroom. I've always been told that valves tighten with age (rather than get loose) because as they wear into their seats they get closer to the rocker and have less free play.

If this is the case, wouldn't these engines become LESS susceptible to the rattle over time as the dry lash becomes smaller due to normal wear and tear? Or are there other dynamics with the HLA system that offset this? (Note that Tom's post implies that tightening the dry lash to 0.75mm would help mitigate the problem.)

 

I'll relate to you my experience with my dealer and my clatter issue. Last year they did a "purge" with no effect. Yesterday they replaced the timing chain tensioner. I asked multiple times if this was a redesigned tensioner or just a same part replacement. At first the service advisor did not know of any new part, but called some head engineer on the west coast. This is what was related to me:

A redesigned tensioner has been available on new builds since Dec '08. The part is not yet available to the dealer yet.

I feel the dealership is being up front with me and trying to resolve this issue.

Do we have any occurances on cars built after Dec '08? (That would mean clatter almost out of the showroom!) We may have to wait and see.

 

This language appears in the abstract for a U.S. patent application for a hydraulic valve actuation system with valve lash adjustment:

"The hydraulic actuator adjusts the valve lash during one or more rest periods. [emphasis mine] By adjusting the valve lash during the rest periods, the hydraulic actuator essentially adjusts the valve lash in response to one or more of the actual physical parameters of the valve during engine operation."

If the MINI's system operates in a similar fashion, could it be using a rest period after an inadequately warmed up engine in its valve lash adjustment calculation, and thus getting it wrong?

Here's the reference if you're interested:
http://www.patentstorm.us/patents/7347172.html

 

Also, since timing chains tend to stretch slightly over time, this would add credence to BMW/MINI's theory of the cause, as it would explain why some cars don't show symptoms right off the lot, but develop the noise over time.

I agree that Tom's theiry sounds reasonable, however, it is still only a theory. While Tom is quite knowledgable, the explanation he has posited is not the direction BMW/MINI has taken their investigation. Not that I trust BMW 100%, but I would hope that after all of this time they would at least have narrowed it down correctly (i.e. to the timing chain tensioner and not the HLA's).

 

I have a '91 Miata and though these are very robust engines they can also develop a rattle in the valve train. It is caused by the HLA's, typically on cars that have not had frequent oil changes. At some point the lack of oil changes starts to gum up inside the HLA's and you get valve train clatter. Some people say thinner oil will fix it, others say to go to thicker oil. My car has had 3,000 mile oil changes its entire life and at 83,000 miles there are no valve train rattles.

As far as 'don't go over 2,000rpm till the rattle goes away', forget that. I have a four year warranty and if the dealer says that it is normal, then drive the crap out of it so it will fail before the warranty is up

 

Ha, RickDM, I agree with you about the BRG! BMW has it way too dark.

I'm familiar with hydraulic lifters from overhauling aircraft engines. The rest period during which the lifters adjust themselves are the intervals when the valves are closed and the engine is running. Any valve train slack is taken out by pressurized lube oil entering the HLA during that time.

What these lifters will sometimes do is deflate when the engine is stopped and the lifters have to hold a valve open for a long period of time. The pressure in the valve train will force the oil past the one-way valve and compress the lifter. This causes that valve to have a lot of slack until the HLA pumps back up, but that just from lack of oil, not because the lifter has filled with air.

The usual concern with improper valve train clearance is bad valve timing, and it takes a very large amount of slack to cause valve failure due to hard closing. That no-one has posted about an engine failure due to a broken valve suggests to me that deflated HLAs may still be within tolerance and isn't causing a problem. Like Rick said, drive the heck out of it, that's the only way to tell if it's a problem.

 

An interesting idea. So if it turns out to really just be a "noise" problem then nothing changes. But if there is damage, it'll happen sooner rather than later (hopefully while still under warrenty). I guess Mini would have a bit harder time saying a dropped valve is "normal" eh?

 

Hi gang, as the starter of this thread, (yes, a dubious distinction) I have no real update to report, other than at 7K+ miles on this car, and with a year-old tensioner replacement service action, there is no real change. Sometimes it sounds bad, most times it doesn't. There is no consistent behavior. The car can sit undriven for 13+ days in single-digit weather, and its quiet(relatively) at start-up. I can commute 3 days in a row, and on the 4th day, it sounds like its got 200,000 miles on it. So, when the lease is up, back it goes, the dealer can worry about it. Don't have the energy to worry about it anymore.

 

Just got my 07 mcs back from the dealer. They installed the updated tensioner and told me if the noise comes back they will put a new engine in the car. The part was on back order and I had to wait 23 days for the install. Cars been running like new since I got it back....lets hope it stays that way. Dealer admits they have put new engines in after tensioner update did not solve issue.

 

One thing to note, the noise on my MCS got much worse and way more frequent after I drove it very very hard on a cold morning without giving it a warm up. After that it sounded like a tractor every morning.

 

i've just had it with my car. my cold start noise gets worse as time goes on, even went as far to have a passerby in a parking lot ask me if it was a diesel. i have never driven by car hard, never taken it to a track, even let it warm up 'til the noise went away. it just gets worse and worse.
i have taken the car repeatedly to the dealer (for other issues unrelated to this one) and mention the cold start problem each and every time. each time they tell me something different. from it's normal to "oh, there's no fix for that yet" (funny thing is it is the same service advisor!). i asked why if it's normal to make this noise, how come my loaner minis never do... and i get no answers....
so when my lease is up in two months, back the car goes. i will never buy another one. while it is fun to drive, it is not fun to have to take two days off a month to drive to the dealer (an hour each way, without traffic) for service for things that shouldn't need to be fixed on a car this young, and to have it sound like an old mercedes diesel truck.
they lost someone who could have easily been a loyal customer. not only that, but when friends ask me about the car, i tell them stay away. it is not worth the headache and the heartache.

 

BMW will not spend the money to fix the problem. Tom who posts at Michigan Minis:

http://www.michiganmini.org/forum/in...topic=3115.195

has, IMHO figured out the problem. It is with the hydraulic lash adjusters (HLAs)
BMW undoubtedly knows this as well. BMW will never admit engineering errors. This is very sad as the engine otherwise seems pretty good.

 

surely somewhere in this great land of ours there has to be a demo, loaner, guinea pig MC/MCS with the cold start problems BAD where BMW could attempt Tom's fix(es).

and it gets me that BMW wont even acknoledge him nor his credibility, for his company built valve train parts for the venerable Tritec.

and yeah add me to the list this last tues: week 39 build 09 (see sig) only 2468 miles, afternoon at work parked 8.5 hours, lasted about 20 seconds, 40F parked level, idled smooth otherwise. no problems since, inc yesterday 530 am and 12F. log book in glove box. dealer informed. After my last MINI, it will not take much for me to bail for good.

 

Of course not. until they build a new motor with better engineered hlas (or recall to shim the exisiting ones and reduce the valve lash tolereances) this problem will continue.

and whatever happened to the vacuum pump theory

BMW/PSA tech execs right now have themselves in a dark room, and they're stumbling over each other trying to find their way out--and to a possible solution they're too stubborn or blind to see and try.

 

I agree that BMW is either too proud or really scared to publicly admit the problem; however, the bigger problem is that there are too many of the MINI faithful that are still "drinkin' the Koolaid." Thay laugh it off as being either isolated to a few reported instances, that it's a normal occurrence, that it's abnormal but not doing any damage, or it's abnormal and they're going to blow it off because they plan on dumping their car prior to warranty expiration. They blindly conclude that since NAM only represents less than 1 percent of total owners, the reported frequency is overblown and the issue is in the noise.

It was amazing to see the Koolaid guzzlers lambaste the OP in another thread just because he expressed his personal preference to wait a few months on a new MINI purchase to see if BMW could get their act together on this and the freezing throttle body issue before he plunked down his $30K. How dare he not love the MINI to the extent that he would plunge headlong into ownership without pausing for a little rational thought.

As long as BMW observes that the majority of potential buyers are indifferent to these issues (and they must be watching) what business motive do they have? The lemmings will just keep on lining up at the dealership door.

 

i knew my MCS reminded me of something- the 1941 farm all tractor i used to ride with my grandfather when i was a kid!

 

but with the direct injection tickticktick these cars are kinda noisy at startup to begin with-- but what I heard tues was something much more metallic and harsh--yet the engine stayed at 900 rpm OK fine, with no funny exhaust look or smell.

And Tom's rationale for the randomness of it all depending on where the camshaft cycle comes to rest during the previous engine power-down makes a lot of sense.

My SA is very open minded, as well as frustrated with their attempts to fix this problem, so he's printed out Tom's tech writeups and is discussing them with his lead tech. He told me yesterday that they may attempt to try the manual lash adjustments, HLA shims, and valve end caps on a troublesome 07 MC loaner that has the rattle bad year-round, just to see if these fixes mitigate the problem.

 

Yup, me. Only 2500 miles on an 09.

My question: has anyone with a factory JCW reported this issue yet?

 

Nope. My dealer has two 07 MCs with the rattle.

 

0W-30 synthetic is now an approved oil for the 09 MCS, page 105 of the manual. Even my SA didnt know this.

 

Retrofit Tritecs?

 

Finally! Mine rattled at 900 rpm and did not vary, silk, and was MUCH louder inside the car than out (the amplification tube?) "Toy snowblower" is one accurate descriptor. the fluctuating rpms are a whole different issue.

Tom on MMC is certain that it's the HLAs and excessive dry valve lash, esp. if the car starts and runs OK for a few seconds before the death rattle appears (like mine did.)

 

Tom admitted to me in a pm a few days ago that 0W-30 Castrol synthetic did not help.

 

Very. After all it is a Stage 1 JCW. so much for that