I have a 06 w211 and while returning home I noticed a significant drop in power-like it was running on fewer cylinders.
Put the OBD on and said misfire on#4. When I checked 4 and the coil everything seemed ok. The coil fired strong etc. I did notice some of the other plugs were loose (barely hand tight) and what looks like blowby was all over the coils.
Needless to say after cleaning them all and torquing them all to spec I still show a misfire on number four. Checking the wiring and everything else around it seemed okay.
Any ideas on what to check next? The car does have 220,000 miles so I'm hoping it's not a ring issue Etc.
I would upload some photos but it says it's not working.