E55 Kompressor missfire
Thread Starter
Junior Member
Joined: Jun 2009
Posts: 15
Likes: 0
From: Sudborough northants
w124 300e
E55 Kompressor missfire
Hi guys
I have a really anoying missfire on my E55, to start with the diagnostic showed both front lambda sensors were shot so i changed them for proper bosch ones and i double checked the part numbers so they were correct.
the only mods to the car are a remap and bigger throttle body done by West tuning in the UK. The anoying bit is it does not log a misfire as a DTC on the ecu so im a little stumped and any help would be much appreciated.
Kind regards Jamie
I have a really anoying missfire on my E55, to start with the diagnostic showed both front lambda sensors were shot so i changed them for proper bosch ones and i double checked the part numbers so they were correct.
the only mods to the car are a remap and bigger throttle body done by West tuning in the UK. The anoying bit is it does not log a misfire as a DTC on the ecu so im a little stumped and any help would be much appreciated.
Kind regards Jamie
Senior Member
Joined: Jun 2009
Posts: 253
Likes: 2
Viking War Ship
The ECU recognizes misfires by calculating the acceleration of the flywheel at each cylinder in the firing order. It will throw a DTC/CEL and then shut off the cylinder if it sees too many of them from that cylinder. Exact number, I'm not sure. How are you logging the misfire if the computer in the car isn't sensing it?
Super Member
Joined: Oct 2009
Posts: 661
Likes: 3
From: Saudi Arabia - Qatif
Brabus K8 E55 05
When installed 82 TB for my brabus E55, the mechanic used Star Diagnostics to increase the amount of fuel coming to the car as I have now more air coming there is an option inside SDS. I don't know if that would help or not, now all I need is to get tune and return the normal fuel coming to the engine.
Thread Starter
Junior Member
Joined: Jun 2009
Posts: 15
Likes: 0
From: Sudborough northants
w124 300e
The ECU recognizes misfires by calculating the acceleration of the flywheel at each cylinder in the firing order. It will throw a DTC/CEL and then shut off the cylinder if it sees too many of them from that cylinder. Exact number, I'm not sure. How are you logging the misfire if the computer in the car isn't sensing it?
.Its leading me to think it may be gearbox related as my last e55 (w210) had the clutch plates in the box breakup causing it to be juddery and seem like a missfire, this car has full service history and only 52000 miles.
Super Member
Joined: Apr 2003
Posts: 681
Likes: 4
w212 E63 / 996tt
Its not logging and faults except my rear number plate lamp buld being blown.
Its leading me to think it may be gearbox related as my last e55 (w210) had the clutch plates in the box breakup causing it to be juddery and seem like a missfire, this car has full service history and only 52000 miles.
.Its leading me to think it may be gearbox related as my last e55 (w210) had the clutch plates in the box breakup causing it to be juddery and seem like a missfire, this car has full service history and only 52000 miles.
Are you actually hearing your car "Bang---pop----boom"?
My ECU has a P0308 code stored, "misfire in cylinder 8". My tech says that it could be from tons of things. Bad gas, vacum leak, etc....
http://www.obd-codes.com/trouble_codes/
Scroll down to DTC codes.
Thread Starter
Junior Member
Joined: Jun 2009
Posts: 15
Likes: 0
From: Sudborough northants
w124 300e
Found the problem, my mate at 
HA Lock motor engineers in the UK put their start diagnostics on it and we found by him testing verious things that the torque convertor is fubar and needs rebuilding and it explains the way the car is behaving. Next question can the torque convertor be uprated at all?.
HA Lock motor engineers in the UK put their start diagnostics on it and we found by him testing verious things that the torque convertor is fubar and needs rebuilding and it explains the way the car is behaving. Next question can the torque convertor be uprated at all?.
