MCS Engine noise when cold

[dneal]

If the knocking noise goes away as the car warms, it seems that your problem is piston slap.

Many automakers are designing their pistons with much shorter skirts in order to minimize weight, allowing the piston to "wiggle" in the cylinder when cold. As the piston warms, it expands which fills the gap causing the knocking sound to go away.

Google "piston slap" for more information.

[eggtruck]

Mine has done it a couple of times too - if you drive with it like that the car feels like it has very little power - almost like not all the cylinders are firing.

The only thing I can compare it too was on a Seat Leon 20V Turbo Cupra - the coil packs kept failing on it and made it missfire.

Remember guys, we are the MINI R56 test pilots!!

[Prowse]

Looks like the Citroen-Pug chaps had more input to the engine design than was advertised. Pug always did make reliable, but noisy diesels!

Seriously though, that noise can not be good, any components that are clattering about like that are surely going to be causing damage/wear.

[JG.26]

I think its a case of welcome to the delights of French engines

Reading todays Mail on Sunday test of the 207CC GT which basically uses a slightly detuned engine which is in the S, same comments that it sounds like a diesel and is noisy, but quietens down when warmed through. I think their diesel engines are actually quieter than the petrol's

[wiggis]

Hmm. I've listened to the recording several times now and .......

I think the problem is to do with the turbo. The design uses a twin scroll turbo, where the exhaust gases from 2 cylinders feed one of the scrolls, and the exhaust from the other two cylinders feed the other scroll, and the feeds are separated in the exhaust manifold.

Now what if the turbo wasn't spinning freely?. It would put considerable back pressure on 2 of the cylinders, and a slightly lower backpressure on the other 2 cylinders (the two scrolls act almost as different turbine 'gears'). If this was happening, the engine would run very badly and would be reluctant to rev up, and could quite easily sound like the recording posted. Perhaps when the turbo eventually warms up, gets good oiling through, and starts to spin more freely, the problem goes away?

So what might cause this? Even a small piece of metal swarf left over from the manufacture somewhere inside the engine could damage the bearings in the turbo enough to do this if you were unlucky enough to have such a piece of metal floating around and it were to find its way to the turbo instead of being trapped by the oil filter.

This would also explain why no one with an R56 Cooper (as opposed to an S) has reported similar issues.

Just a thought based on pure speculation .......... If I owned a Cooper S and didn't have this problem, I'd seriously consider an oil flush and change shortly after running in - just in case.

[chipcooper]

My MCS is very lumpy on tick over and very jerky when driving from cold! I wonder if it's all related! I love the car though and wouldn't change it for anything else!

[Purple Dave]

Quote: Originally Posted by wiggis (original)

Just a thought based on pure speculation .......... If I owned a Cooper S and didn't have this problem, I'd seriously consider an oil flush and change shortly after running in - just in case.

Exactly what I intend to do. 20,000 miles before an oil change is IMO madness, especially after a running in period. All that fine swarf floating around for 18 months or so can't be good

Better safe than sorry.

[Purple Dave]

Quote: Originally Posted by chipcooper (original)

My MCS is very lumpy on tick over and very jerky when driving from cold! I wonder if it's all related! I love the car though and wouldn't change it for anything else!

Mine is a little lumpy at tick over too. Not noticed it being jerky though.
I'll have a chat with the service guys when I have an oil change in a couple of weeks.

[CBCooper]

Ok, the dealer has had the car since Tuesday, it made the noise as in the video i took for them, they ask for some advice from BMW and they replied that it was a normal noise, some make it, some dont. Apparently its an air pump pipe? if you take the pipe off it stops making this noise. Nothing to worry about....
Picking my car up in afew hours, what do you guys think, im no mechanic but that noise is wrong and not normal at all in my eyes.

CB

[craigd]

Be very wary and ask for their findings in writing.

I have been lied to on 2 separate occasions in the last 3 months by MINI, so best to keep yourself right and get them to tell you what they have done and what exactly their findings are..

hope it works out OK..

[Martin F]

A lie is " an intentional false statement" according to the OED. Whilst the statements made to you may have been incorrect, how do you know that they were intentionally false?

[Morri7]

Hi
Have just listened to this and think it sounds terrible - how can that be normal?! Could you try a different dealer and see if they come to the same conclusion?
I have an R53 MCS and it made a noise very similar to this a few times when started from cold but it would not make it for the dealer when I took it to them - typical! It seems to have resolved itself as it no longer happens. I always thought that it was a lack of oil but the levels were fine.

[CBCooper]

Just a quick update. Got a call today to say that they had another reply from BMW about the noise and that there response was to change the Cam Chain Tensioner. Car is now booked in but have to wait 10 days for the part/parts to come from Germany.

CB

[KenL]

So much for it being the "air pump pipe"

What is an air pump on a car anyway?

[PmP]

That sounds like a misfire almost!

I suppose you cant tell if its down on power? There is a similar ticking noise intermitent in my R53 S upon cold start up, but not to that extent, I would take your car back and demand a replacement or a full refund!

TBH, im not suprised so many R56 owners have had bother so far. Any new car when it comes out always has the odd problem, but the original BMW mini which I had was horrendous for problems and alot of people had when it was launched.