I have a CLubman s 08 and just shy of 60k miles. I had a timing chain issue once in its history and dealer fixed it for me on their dime as it happened 20 min after pulling out of service....

Now I get a misfire engine code on cold start, sputters and stalls. This will repeat unless I give it gas and than it functions fine. I don't see a dip in rpm when coming to a stop.

So I decided after seeing HPFP threads relating to this I ran seafoam trough the gas tank. SOunds much better but again problem persists.

IT should also be noted that after the troubled cold start restarting after that is no problem. If I cleared the code it will not pop back up on a warm start at all.

So being I made no leeway I took it in to a local guy every one I know uses as I am out of warranty, he runs all his tests says I def need plugs but not cause of the misfire. But hes finding oil inside the super charger and they did a leak test they think the supercharger is pulling oil into the intercooler and that's causing the misfire and a sign the turbo is failing.

BEing I ran the seafoam and I know about how bad carbon buildup can be on DI does this make sense?

 

Oil in the intercooler doesn't necessarily mean that the turbo is failing. The same oil that causes valve carbon deposits also ends up in the intercooler - it's coming from the PCV system. There are threads that discuss oil catch cans in which the PCV system is discussed in depth, so I won't try to cover that ground again. If the valves have heavy carbon deposits, Seafoam may not be enough - it's better as a preventative treatment. At 60K, you probably do need spark plugs in any case, and the valves almost certainly have carbon build-up. New plugs may reduce the problem for a little while, but they can't do anything about valve deposits. Turbo failure at 60K is premature, although possible if the oil never got changed. If the turbo is failing, you'll be burning oil - possibly a lot of it. Enough that your plugs will be fouling, and you might even be making smoke. My suggestion: Go for the plugs, then have your valves walnut blasted. The next thing to consider would be the fuel pump. Keep us posted, and good luck!