I did 5 of the 6 on my M104 engine and it is was routine. To get to the last one in the middle, IIRC, I need to remove some air hoses and I want to be ready with replacement parts in case the hoses disintegrate. If your M103 uses seals and insulators, you'll need those too. These things are not cheap and it may be an expensive way to hunt down a misfire.


glenmore
1991 300CE
2000 C280