M156, bad coil?
Thread Starter
Junior Member
Joined: Sep 2016
Posts: 54
Likes: 3
From: OKC
2008 E63
M156, bad coil?
So my 08 63 has been doing this thing where it will start to misfire, throw a check engine light, and then be perfectly fine when I turn the car off and back on. It usually more than a month between issues and usually only after having the throttle to the floor for a couple of seconds. I kept my scan tool in the car and when it did it again I was able to get a code P0304 for the #4 cylinder misfire. The spark plugs have 16k on them. Does this happen a lot to this motor? I have only owned the car for 19 months.
MBWorld Fanatic!
Joined: Apr 2009
Posts: 6,020
Likes: 532
From: Alexandria, VA
07 E63 AMG, 10 C63 AMG, 07 E63 Designo, 07 E350, 09 C300, 07 C230
No, this isn't a usual thing for the M156 engine. Have you diagnosed your issue, and what does the code actually say is wrong?
I've owned two E63's and one C63 with the M156 engine, and only had one CEL, do to a bad gas pedal throttle sensor at WOT.
But never for cylinder misfires.
I've owned two E63's and one C63 with the M156 engine, and only had one CEL, do to a bad gas pedal throttle sensor at WOT.
But never for cylinder misfires.
Member
Joined: Oct 2017
Posts: 216
Likes: 17
From: Boerne TX
E63 and GL450, ML350 bluetec
Which code does it show? You may want to stop by a indy shop and have the car scanned. The codes are stored in xentry so you will be able to see what hit. The M156 will go out of time, but even mine was off and showed no codes for it, also I have heard they have vacuum issues and tons of oil gets ingested into the intake, mine had a half a cup of oil inside. Pulling the spark plugs will tell you a lot.
Super Member
Joined: Sep 2009
Posts: 941
Likes: 74
From: Orlando FL
a unicorn tuned p30 e63
A simple thing that I would do is pull the coil out of 4 and put it into 3. I have a odb2 scanner and i was getting a miss on 2 and 4 and i kept clearing code and on the 3rd time it told me the truth. O2 sensor. Bank 2 controls 1-4 (pass side of motor). To keep it simple swap the coil. Last one on pass side with number 3 in front of it and see what it does.
