So after a long road trip back for attending MINIs at the Glen at Watkins Glen Speedway I ran into a bit of a problem. About 30miles from home while merging onto the highway under heavy acceleration, I get a drive train failure. Car immediately goes into limp mode. Run a scan and it says misfire in cylinder 4.
Take it to dealer and they tell me the spark plug cracked but they give me no clues as to why that might have happened. They replaced the plug and it drove home fine. Did they fix the actual problem, or just the result of a bigger problem that will reappear?

Now I'm leaving for another rally today and have no confidence that it won’t happen again.

What the heck could have caused this? This is a well maintain non beaten on 2018 JCW F54 with just under 15k miles.

Any thoughts would be appreciated.

 

Could have had a slight crack when installed new, could have been a defective plug from the start....there is lots of heat at the plug, and they are in an area where no cool air can get around them to cool them off......personally, I would not worry about it......but if it still bothers you, maybe find an independent repair shop that you trust and install a brand new set of plugs and have peace of mind

Bryan