I have mini r56 S 07 automatic the car starts with CEL with loss of power cleared several times but did not go away with three errors multiple and cylinder 3 & 4 misfire detected.

It's really hard to drive and if the gear in D or R with full stop the car will switch off I have to put in N to keep it running, and engine keep shaking from idle up to 2000 rpm after that is ok except the loss of power.

We have checked the knock sensor, spark plugs, injectors, coils, and the HPFP but no luck. The dealer said the cylinder 3 & 4 have low pressur but they could not figure out the reason.

Any idea?

 

A really bad case of carbon build up on the intake valves? Did they do a leak down test? If so where did the air go? This can tell you what part is bad. If it is coming out the intake then the valves are fried or there is enough carbon build up to cause them to not seat correctly.

I don't know if seafoam would help at this point or not, they have a new spray kit that would be much easier than the old method.

 

+1

 

did you ever figure out the problem? i currently have cylinder 4 misfiring :(

 

I'm assuming they did a compression and/or leak down test if they discovered that.

It's pretty self explanatory that there are issues with the pistons or rings in those cylinders if they are lower than the rest. "not figuring out the reason" is a bs excuse....take it back, day after day if you have to. Or try another dealer in your area (if you have one)

**edit, just saw this thread is way old lol

 

haha i've brought it back from the dead..

I can't wait to hear the excuse when I bring my car in tomorrow. I've been telling them for awhile now that something wasn't right and that it felt like a misfire...they said they couldn't reproduce the problem and to bring it back when there was a code to check. Since then it's overheated for the second time and had to get a new water pump. I asked them to do a compression test to see if anything was out of the ordinary but they never did it. Finally today when I was chugging my way down the highway the check engine light popped on. I have a feeling the problem stems from the work they did on my engine right when I bought the car. Nothing but problems since I got it :(

 

ive had the same thing 07mcs. backfire thru the intake blew the turbo intake line off 3x and they tell me the hose was too tight or too loose. ridiculous. also had a complete loss of power with backfire in the exhaust and the speed dial going from 70 to 0 to 70 in 2 seconds. going to bring it back again 4th time tomorrow.

 

Ugh! Drives me insane that they will ONLY look at the car when it throws a code. My dealer's favorite line "is it throwing any codes?" me: no... them: "well its fine then, just bring it in if it throws a code"

It's like HELLO, I'm 99% certain my car isn't running right...let's be proactive and catch the issue BEFORE it throws a code. That would be asking to much.

Just stay on them, like I said bring it back over and over till its fixed.

 

My low pressure led to no pressure and a new long block engine
At first I thought I had a carbon build-up issues with the misfires.. eventually she was running like a tractor and when they finally pulled it apart discovered that the bottom of the piston was broke. Top and valves were fine. Only explanation was that is was a manufacture defect... 63k... fortunately I had the extended warranty.
Good luck...

 

Oh no worries, I'm persistent. I have no problem going down there when they don't return my calls =P

It would be nice if they believed in preventing problems or catching them before they've snowballed into something much more intense instead of just semi-fixing them :( maybe I need to find another dealership, although a lot of them seem to be just as bad as mine

 

Good luck! I'll keep my fingers crossed for you while I'm waiting for a diagnosis on mine