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2015 X5d Sputtering on 1st start 'sometimes'

11K views 10 replies 5 participants last post by  John Galt 
#1 ·
Have had this happen a few times over the past month. When I first start up and pull out of the garage my engine sputters and the revs drop and jump up and the truck feels like it is going to stall. It's been in the 80/90s here so it isn't the cold. I have depleted the fuel and then filled back up and was good to go and I just happened again this am. Totally annoying... 15k on the motor. Anyone else with a diesel having this issue?
 
#2 · (Edited)
I have had a very similar issue recently with my 35d. It is not on cold start-up (although unlike you, my vehicle is in my cool garage when cold-started), but when the vehicle sits out in the heat (which DOES sound like you). No problems on cold-start but when sitting in the heat, or after driving for a period, shutting down, and then restarting in the heat, the vehicle "stutters/shudders" one time within the first 10 seconds of start-up.

I had it in for service yesterday (at 45,xxx) miles for an oil change and tried to get them to duplicate the problem but to no avail. I think the one constant is 85-90+ degree heat. Yesterday was in the low 70's and I couldn't duplicate the stutter. I told the SA that it felt almost like someone else was in the vehicle and shook it from side to side gently when it happens, and I can also hear the engine "skip" a stroke, for lack of a better descriptor.

My SA said there were no fault codes stored and that he could not find anything from BMW NA related to this. He did mention that with these increased-efficiency engines, he has a theory that the computer sometimes misses the fact that the engine (perhaps the actual engine, not engine temp, as in a hot car sitting in the sun) is hot and tries to start with the "cold" fuel/air mixture, then immediately realizes there's lots of heat and cuts/modifies the mixture.

The service tech who took a test ride with me said that in the E70 35d's there were actually pneumatic engine mounts that changed their level of stiffness during idle, some throttle, WOT, etc. This was all news to me, and I have never heard of such a thing, but these guys would know best. He said that sometimes the internal setting of the pneumatic mount got mixed up and the mount was too stiff on idle, hence more felt engine vibration in the cabin. I think the first theory sounds better than this one but who knows... I'll monitor it closely and report back if I learn anything new.

-John
 
#3 ·
I have had a very similar issue recently with my 35d. It is not on cold start-up (although unlike you, my vehicle is in my cool garage when cold-started), but when the vehicle sits out in the heat (which DOES sound like you). No problems on cold-start but when sitting in the heat, or after driving for a period, shutting down, and then restarting in the heat, the vehicle "stutters/shudders" one time within the first 10 seconds of start-up.

I had it in for service yesterday (at 45,xxx) miles for an oil change and tried to get them to duplicate the problem but to no avail. I think the one constant is 85-90+ degree heat. Yesterday was in the low 70's and I couldn't duplicate the stutter. I told the SA that it felt almost like someone else was in the vehicle and shook it from side to side gently when it happens, and I can also hear the engine "skip" a stroke, for lack of a better descriptor.

My SA said there were no fault codes stored and that he could not find anything from BMW NA related to this. He did mention that with these increased-efficiency engines, he has a theory that the computer sometimes misses the fact that the engine (perhaps the actual engine, not engine temp, as in a hot car sitting in the sun) is hot and tries to start with the "cold" fuel/air mixture, then immediately realizes there's lots of heat and cuts/modifies the mixture.

The service tech who took a test ride with me said that in the E70 35d's there were actually pneumatic engine mounts that changed their level of stiffness during idle, some throttle, WOT, etc. This was all news to me, and I have never heard of such a thing, but these guys would know best. He said that sometimes the internal setting of the pneumatic mount got the mixed up and the mount was too stiff on idle, hence more felt engine vibration in the cabin. I think the first theory sounds better than this one but who knows... I'll monitor it closely and report back if I learn anything new.

-John
Mine is garaged as well except when I'm at the office when it is outside there. It only happens when I'm leaving the garage which is so strange. I talked to my SA this am and he said that it could be the Diesel was bad but unlikely due to the fact I ran it dry and filled it back up from a recommended BP station here. Didn't know about the engine mounts! These trucks are insane when you think about the tech in them. I'm going to see if it continues and if so hopefully it's been complained about enough then that BMW NA gets on it.
 
#4 · (Edited)
Have the fuel filters changed. It's much more common to get contaminated diesel fuel that gasoline. Diesel fuel filters need much more attention than gas. Typically if you are experiencing any erratic engine behavior in a diesel a good place to start is the fuel filters. Always buy your fuel from a place that sells quite a bit of it is a good tip. My father in law has a Ford F-350 diesel he tows with, at 7800 miles he experienced a loss of power and rough engine operation, a simple fuel filter change and it was like new. Heat very rarely with effect a diesel like it can a gas, Very Cold is a completely different conversation.
 
#6 · (Edited)
***Another edit to add***

Now I'm nearly stalling out when slowly backing up in reverse at or just above idle. Would be all over BMW but my wife delivered our baby boy today so I certainly have more important matters to attend to. So strange! At least one more data point to add. I'll report back when we figure out what the hell is going on.
 
#9 · (Edited)
***UPDATE TO ADD - PROBLEM FOUND/DIAGNOSED:***

My 35d was getting to the point where it would shudder/shake upon nearly every warm start after the vehicle had been driven and shut off. It was then starting to shudder to the point of almost stalling when slowly backing up. It's been at the dealer for the past week and they were finally able to figure out what's going on. They collected a bunch of data and uploaded it to BMW NA who stated the following:

"Check the EGR cooler for soot buildup."

SURE ENOUGH- there was a tremendous amount of soot buildup in the EGR cooler and it will be replaced. My service advisor said while BMW has not released a bulletin on this yet or recall, they are closely monitoring reported issues. I'll report back once fix is done, as well as any codes listed on the paperwork.

-John
 
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