2010 535i xDrive w/51K miles. Yesterday morning startup (temp in the low 50's) yielded a rough idle which did not smooth out within 1/2 mile. Felt like the car was bucking (like riding a bike with a wheel out of round) and noticed a rotten egg smell. Pulled over, turned the car off for a couple of minutes, started it back up and it ran smoothly the rest of the day with no odor. This morning (again temps in the low 50s), rough idle of the same magnitude, backed out and put in drive, same bucking, check engine light this time and the rotten egg small again. Vehicle status check yielded all systems OK. Brought it to the dealership this morning (under CPO). Awaiting Monday for service to check it out. I found some threads on rough idle/cold starts (most seem to always call out the HPFP), but the rotten egg smell is throwing me. Anyone thoughts on the matter are much appreciated. Thanks, -Mike
Not so much a bad cat but a really bad misfire (which destroys cats). Most likely with the temps dropping the injectors are starting to leak giving you a bad smell with the misfire. If the index number is below a 11 you will need to replace all of them. Most likely not a HDP since the car can be restarted to run fine. Kinda of a common issue on the N54 engine hence the updated parts.
Steven S & Charlson89, Thanks for your comments. Charlson89 - Can you let me know what you are referring to by, "HDP" and "updated parts"? Thanks, -Mike
HDP- is the high pressure fuel pump. And by updated parts I mean the injectors for your vehicle has a revised version. There a number on the injectors called index numbers that determine what version they are. The current number is 12 so anything 11 or higher is good means it's the newest version of the injectors. Any injectors with index lower then 11 have issue with leaking and causing misfires. Hope that a little clearer. Let us know how it turns out.
Charlson89, You were correct. A service advisor left me a voicemail today that said it was the fuel injectors that were bad. I tired to follow up, but it was late in the day. Work will be performed tomorrow. Would a service advisor know as to the index # or is this better left for a tech to advise? Thanks, -Mike
Mike, That really depends on the service advisors skill level most of the time it is the tech to know that stuff.
Charlson89, Picked the car up this evening. Too late to speak with an advisor, but the paper work noted that the old injectors were series 7. They replace all 6 with pn 13-53-8-616-079 and new decoupling elements. From what I can tell, these are the new injectors. Car ran fine this evening. We'll see how it starts up in the morning. Thanks again for all your feedback. -Mike
