Someone please help. My wife's 2009 Mini Convertible ran fine. Then she ran it hot. I replaced the head and one piston. Both damaged by a dropped valve seat. Put it back together and it ran fine for about 2 weeks. Now it runs fine for about 30 miles. After that it has a rough idle and sets a code for a cyl 1 misfire. It however funs fine going down the road. When it cools down it runs perfect again. I checked the compression and it is 130lbs on each cylinder.
I have changed all of the following items on cylinder one
Spark Plug
Ignition Coil
Fuel Injector
I have also changed
Throttle Body
Purge Valve
Vanos Valves
Temp Sending Unit
Thermostat and Housing
Please someone give me and ieal