Hi,

I seems that one the car has warmed up and been driven for 20 min or so it runs real smooth and quiet..then, ofter maybe 40 min it seems a bit rougher. Little tappy or rattle....chugging along not as smooth..I am thinking an oil change, filter changes, and valve adjustment...but why would it be smooth and then go not so smooth? Thoughts?

Thanks,
-Kurt

80 240D