A Consistently Intermittent Cylinder Misfire Signal.

[NorthCountryGuy]

Guys,

The X6M is getting a Drivetrain warning and going into limp mode. This is what was found on the Foxwell at cylinder 5. Got it back to my garage. New Bosch plugs and coils from FCP all around. Still on occasion would get the same warnings. First switched coils between cylinder 5 & 6. Still a cylinder 5 warning. Then switched the plugs. Still a cylinder 5 warning.
Had to go to BMW for I had a sound system problem covered under warranty, so I had them plug in for the diagnostic work up. They said they couldn’t find anything. They said the fuel injector was fine. They said they put 80 miles on the car soft and aggressively but couldn’t find a thing. I told them to reprogram the car. After being parked at work he got these on the way home.

Where do we go from here ?

Thanks in Advance
Craig

[Sophisticated Redneck]

Originally Posted by NorthCountryGuy

Guys,

The X6M is getting a Drivetrain warning and going into limp mode. This is what was found on the Foxwell at cylinder 5. Got it back to my garage. New Bosch plugs and coils from FCP all around. Still on occasion would get the same warnings. First switched coils between cylinder 5 & 6. Still a cylinder 5 warning. Then switched the plugs. Still a cylinder 5 warning.
Had to go to BMW for I had a sound system problem covered under warranty, so I had them plug in for the diagnostic work up. They said they couldn’t find anything. They said the fuel injector was fine. They said they put 80 miles on the car soft and aggressively but couldn’t find a thing. I told them to reprogram the car. After being parked at work he got these on the way home.

Where do we go from here ?

Thanks in Advance
Craig

Has to be injector or burned/pitted valves or low compression in that cylinder, only things left it could be. Start with the easiest: have a compression leakdown test done on it, if it's bad then borescope it, I use one that has a 90 degree dual camera on it (I got mine off Amazon), you can see the condition of the valves and If they are pitted/burned you need a valve job, if they look good then it's a deeper problem with the piston rings.

If cylinder leakdown is good, then just replace the injector. Buy them yourself off FCP and save a ton. If the injector fixes it, then recommend you do all 8, if one fails the rest are soon to follow. I recently did all 8 on my n63 (same injectors/job as the S63). It's not a bad job, just time consuming.

[NorthCountryGuy]

Thanks for the direction/algorithmic approach.