- Joined
- Mar 25, 2010
- Messages
- 15,163
- Reaction score
- 6,337
- Location
- Tonbridge
- Your Mercedes
- W221 S65 AMG - W204 C63 AMG + Various other MB's
- Moderator
- #1
Hi all!!
My S65 is playing about. Having fixed the low boost issues I now have full boost (yay) but have issues with misfires.
Specifically, it misfires above 4500rpm full throttle.
So reading the codes, it was 7,8,9,10,11,12.
I replaced all plugs, both packs (reconditioned) and then drove it. This time, the misfires where much worse, junk recon coil packs. Back they went and 2 new MB packs.
Same as before, misfires above 4500rpm on one bank at full throttle.
New ignition controller
Now, I have misfires on only 7 and 12, but, I haven't tested it more than once yet.
The junk packs highlighted something though. With the recon packs, the misfires where violent and easily recognisable. With the new MB packs, and before, I only know the car is misfiring due to the flashing check engine light, otherwise its unnoticeable.
People love guessing on this engine so any ideas?
Some people have said blocked cat on that bank but the car drives absolutely fine up until that point.
(easily tested with a backpressure tester though)
Others have said fuel filter.
Car drives absolutely fine other than this, but testing is a bit difficult, as you can imagine, as full throttle in second is quite fast....
My S65 is playing about. Having fixed the low boost issues I now have full boost (yay) but have issues with misfires.
Specifically, it misfires above 4500rpm full throttle.
So reading the codes, it was 7,8,9,10,11,12.
I replaced all plugs, both packs (reconditioned) and then drove it. This time, the misfires where much worse, junk recon coil packs. Back they went and 2 new MB packs.
Same as before, misfires above 4500rpm on one bank at full throttle.
New ignition controller
Now, I have misfires on only 7 and 12, but, I haven't tested it more than once yet.
The junk packs highlighted something though. With the recon packs, the misfires where violent and easily recognisable. With the new MB packs, and before, I only know the car is misfiring due to the flashing check engine light, otherwise its unnoticeable.
People love guessing on this engine so any ideas?
Some people have said blocked cat on that bank but the car drives absolutely fine up until that point.
(easily tested with a backpressure tester though)
Others have said fuel filter.
Car drives absolutely fine other than this, but testing is a bit difficult, as you can imagine, as full throttle in second is quite fast....