2nd Gen R56 Cooper S Most liked posts in thread: The Dreaded Cold Start Rattle ...

I guess this is the closest we will get to that timing gear set......:confused5:

[ame=http://www.youtube.com/watch?v=8LqTjIhf2rM]Mini Cooper Clock - YouTube[/ame]

 

I don't think I have experienced this yet.....

But I think my car always sounds like a little diesel :lol:

 

At some point the factory incorporated the fix in production. Does anyone know when this took place as to vin number or date?

 

Unfortunately there are many reports in other online forums of further occurrences and recurrences of the death rattle, both in MINIs that have had the latest iteration of the tensioner fix and in new '09s that rolled off the assembly line well after the date when the latest cam chain tensioner parts were integrated (sometime in March or April of '09).

It is fairly clear that BMW-MINI has not yet nailed down the root cause of the problem and this third iteration of the cam chain tensioner fix is just a band-aid applied to one of the symptoms of the problem. The focus among independent experts in valve train engineering is on the design of the HLAs and the possibility that they don't remain fully fluid filled under certain ECU shut-down conditions along with the driveshaft coming to rest in a particular position.

I don't claim to be an expert...just a voracious consumer of credible information on this topic.

 

There is an engineer on Metroplex Minis who has done the best root cause analysis I've read to date. It's not the tensioner that's the problem, he claims its the hydrolic lash adjusters. (anyway, this allows for impulse shock to propogate down the timing chain and that causes or contributes to the stretching of the chain.) All the BMW fixes to date don't address this issue, so I'm skeptical that any cure will really deal with it. To date, it seems that at best they've found a bunch of related issues and are fixing them one at a time. At worst they've been doing a bunch of band-aids on symptoms. Time will tell....

It's good that you got some help at the dealer. Lots who've experienced the problem just get the brush-off.

Matt

 

From personal experience I'm not sure you'd ever actually hear bad lash adjusters on the MINI engine since them failing sounds a lot like the tapping sound from the DI system itself. This would make me think the rattle is still the chain, just the damage has already been done.

Did the engineer say exactly what the problem was with the lash adjusters? I know older Mitsubishis the orifice was too small and they would clog, not allowing them to fully fill with oil and take up the excess lash. Or is the orifice too large and allowing too much oil to drain out, then not getting sufficient pressure with the MINIs smart oil pump system to refill them quickly enough?
If this engineer's correct a revised lash adjuster and/or reprogramming to have the electric oil pump generate more pressure on cold starts would be pretty easy fixes for MINI to institute.

 

Too much range of motion

so that when they aren't pressurized, the lever looses contact with the cam, and then when the lobe hits the lever you get a shock impulse throughout the valve train. This is what causes the damage. Go over to Metroplex and do some searching. I'm sure it's probably one of the longest threads over there!

Matt

 

Thanks for finding the source..

it was one of those sites I don't frequent very much. But the info in it is good, that's for sure...

Still, I wonder what's going to be next seeing as some of the cars with the "wunderfix" are having recurrence.

Matt

 

Thanks for doing the detective work and tracking it down.

 

Some how http://MM.org doesn't look like it has too much to do with MINIs :lol:

 

Unless he has a cold start noise also. :devil:

Try Welcome to Michigan MINI

 

Also this.
COLD START NOISE

 

If the guy at MM.org is having a problem with a cold start noise, it's not something his MINI dealer can help him with :ihih:

 

So apparently MINI checks the chain to determine if the length is in specification when you have the dreaded "cold start noise". Assuming the chain is stretched beyond specification, you get the "full treatment" (if you are still under warranty, that is). From what I have read about this, a stretched chain can be the cause of the noise of the rocker arms slamming down on the cam lobes. Then once the chain tensioner fills up with oil, the slack is removed, and the noise subsides. One can only hope they are looking for any possible damage to the camshaft lobes, etc. Of course, this damage might not show up until later.

 

See what they are suggesting as a solution over in the UK!

Timing Chain Tensioner (May 2009 on) - R56 at minigenuineparts.co.uk Mini Genuine Parts Mini Servicing Parts & Spares, BM11.31.7.597.895, This is the latest replacement timing chain tensioner fitted from May 2009 to get rid of the timing

 

If only there was something like this for the R56:

For those who don't know, this is a setup that replaces the timing chain on a small-block Chevy with a pair of gears.

 

The first time my 07s had the rattle was 6/30/10 with 49,000 miles. The dealer replaced the timing chain tensioner and the noise went away.

In the past month the noise had started to return with 63K. Took the car into the dealer and complained of a diesel noise on startup.

Dealer said oil in car was slightly low and topped off the oil. The noise was still present. Dealer found noise was caused by the timing chain tensioner running low on oil.

Dealer stated they updated the hydraulic tensioner since it was replaced the first time and replaced it free with no argument.

I'm skeptical about this as the same replacement part number was listed as the first time. 11-31-7-597-895

 

I've had mine changed once already. Seems to be fine ever since.