Hi guys!

Developed a misfire, sanned codes came up with:

P304, cyl # 4 misfire
P300, random misfire
P304, cyl # 4 misfire

I changed the spark plugs and spark plug connectors.

Cleared the codes and the MIL atcivated again.

Code read:
P304, cyl 4 misfire.

My question is: I've had bad coils before and I have yet to see a coil FAIL and it affect only ONE cylinder. Could I possibly still have a bad coil????

Any ideas would be greatly appreciated as I am kinda lost on this one!

Thanks in advance, guys!

__________________
Currently Driving
2006 E320 CDI
1999 E300 Turbo Diesl
2002 ML500
1995 E320 Station Wagon


MBs I've owned
1997 E320 Assassinated by Pine Tree
1987 300E Wife Killed Engine
1981 300D Stretch Limo Total Loss
1970 250 Coupe 212,000 mi.
1974 450sel 184,000 mi.
1974 240D 377,000 mi.
1977 300D 204, 000 mi.
1979 280se God Only Knows!
1983 240D 130,000 mi.
1972 220D 280,000 mi.
1983 300SD 244,000 mi.

I've had 2 bad coils in the past so it is possible.

Which plugs did you use? I don't suspect a coil since it powers 2 cylinders which would likely generate a second misfire code. I would very carefully re-check the plug and the connector or wire on the misfiring cylinder.

__________________
08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

The last coil I changed , only affected one cylinder...

__________________
Jeff

97 E320, ours 217,000miles
91 190E 2.6 daily driver 242,000miles
74 MGB,mine 120,000?
2006 BE350/Proline 21, 50 hours

Jeff, I suppose that it is possible for the coil to negativ ely affect only one cylinder, but how can that be????

If the coil is simultaneously firing both cylinders, then I must assume that it is the same circuit (within the coil), no???

__________________
Currently Driving
2006 E320 CDI
1999 E300 Turbo Diesl
2002 ML500
1995 E320 Station Wagon


MBs I've owned
1997 E320 Assassinated by Pine Tree
1987 300E Wife Killed Engine
1981 300D Stretch Limo Total Loss
1970 250 Coupe 212,000 mi.
1974 450sel 184,000 mi.
1974 240D 377,000 mi.
1977 300D 204, 000 mi.
1979 280se God Only Knows!
1983 240D 130,000 mi.
1972 220D 280,000 mi.
1983 300SD 244,000 mi.

M104 engines have 3 coil wires and 3 high tension leads which piggy back to the next cylinder.

Maybe what is bad is one of these high tension lead wires.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

Former NJ resident...what exit..?

BDB,
When the fault code came up, it was for one cylinder...I thought the same as you...how or why..maybe there is one primary and 2 secondaries..?

I should cut one open..(or wait for an expert)

Another former NJ resident...Morris county

__________________
Jeff

97 E320, ours 217,000miles
91 190E 2.6 daily driver 242,000miles
74 MGB,mine 120,000?
2006 BE350/Proline 21, 50 hours

Jeff!!!......Somerset County, NEW JERSEY and I miss the place, somewhat!

On a 1997 E320, M104 the # 4 cylinder has a coil pack on top of it and is firing the cylinder through a spark plug connector (i'm assuming that cylinder v# 1 is the one in the front of the engine).........I have no problem with purchasing a coil, I want to UNDERSTAND how this coil can break down in such a way........It's almost unbelievable that this type of coil can be defective on only one cylinder

__________________
Currently Driving
2006 E320 CDI
1999 E300 Turbo Diesl
2002 ML500
1995 E320 Station Wagon


MBs I've owned
1997 E320 Assassinated by Pine Tree
1987 300E Wife Killed Engine
1981 300D Stretch Limo Total Loss
1970 250 Coupe 212,000 mi.
1974 450sel 184,000 mi.
1974 240D 377,000 mi.
1977 300D 204, 000 mi.
1979 280se God Only Knows!
1983 240D 130,000 mi.
1972 220D 280,000 mi.
1983 300SD 244,000 mi.

To quote Arthur Dalton " Move the coil to another cylinder & see if the code ( misfire ) moves with it".

__________________
2007 C 230 Sport.