2nd Gen R56 Cooper S Most liked posts in thread: P0302 Cylinder 2 Mis-Fire

Hard to remove that stuff. Unfortunately I'm well out of warranty now (actually I was past warranty the first time, but they good willed it). I'll try to keep it going for another year with sea foam.
Update on the miss-fire p0302: it hasn't reoccurred since swapping the coilpacks, but I'm still getting p115c every couple days.

 

thanks Joel, I'll try some fuel system treatment to see if that helps. I also swapped the coilpack on cylinder 2 with cylinder 1 to see if the miss-fire changes to cylinder 1.

for the p115c:
The dealer replaced the $600 MAF, but the CEL came back a day later (they refunded me for the part).
They were unable to find any air leaks using a smoke test, but I don't know if they checked the valve cover.
I had a catch can, but removed it a couple years ago. Had the CEL with it and without it.
Checking the valve cover sounds like a good idea, thanks!

Oh, one other thing I forgot. When I replaced the bypass valve last spring with the WMW bybass valve, the p115c code didn't come on for 5 months - usually its a weekly occurrence. I thought for sure that had solved it, but the CEL eventually returned. It seems unlikely that the new bypass valve already has issues though, so I think that was a coincidence. Maybe. :skep:

 

no, no engine mods at all

 

did the walnut shells 18 months ago, so it better not be carbon build-up already.:nonod:

 

things have gotten worse.
getting p115c error code every day and accompanied by intermittent power loss. I installed a boost gauge to monitor what is happening.
Occasionally, when I pull away from a stop, I get no boost at all - boost gauge doesn't rise above 0. Sometimes it recovers right away and when I shift into 2nd gear it's fine. Sometimes the lack of boost will last longer and is accompanied by error code p115c. Boost will return after clearing the error code with a code reader, or after a few miles of driving if I don't.
I thought: faulty BOV, replaced it, no change. My mechanic said it was the wastegate, which he replaced - no change. We checked for leaks in the intake, intercooler, everywhere - no leaks. We think that the ECU is sensing a problem and so is cutting boost. Next I'm going to replace the valve cover and gasket as it appears there is a small oil leak at the right side of the valve cover. I really don't think this will help, but I'm clutching at straws now.

History: MAF was replaced by dealer a 18 months ago when I first had p115c (I had no power loss then only the CEL) and also pulled the head and cleaned the carbon deposits and replaced the timing chain tensioner again. p115c returned a couple days later. Warranty was expired so I just lived with the cel.

 

come to think of it, it's very difficult to remove...
New one ordered.

 

OK, time for a FINAL update. I replaced the valve cover (which comes with a new oil cap by the way:wink aaaaaaand.... wait for it......
check engine light (P115c) came back on.:mad2::mad2::mad2:
While at the dealer getting another oil leak fixed, I asked them to have one more go at it. They said there was a PUMA on that. I said there's a mountain lion under the hood? No, a PUMA is like a technical bulletin that says someone else had the same problem and they fixed it this way. So they tried that and replaced the intake manifold part #13712753078 (that's number 8 in the picture)
Did that fix it? no.
They said they could figure it out eventually, it might be another thousand or so, but they'd get it. I said don't bother, this has gone on too long already.
So that's it, I'm done with it, I've finally had it, I completely give up.

 

lol, well I wouldn't be adverse to a low mileage '05-06 JCW, but I'm trying something different.