[Arby1028]

2011 e90 with 95k miles - several times recently when accelerating hard the car "stumbles", rpms drop and I see a cloud of black smoke in my rear view mirror. This has happened 3 or 4 times. This typically happens when the engine is up to normal temperature for awhile, parked for 15-30 minutes with the engine off (going into a store for instance), restarted and out on the road. Upon restart and getting back on the road the stumble/smoke happens. Any help would be greatly appreciated.

[GoRomeo]

Originally Posted by Arby1028

2011 e90 with 95k miles - several times recently when accelerating hard the car "stumbles", rpms drop and I see a cloud of black smoke in my rear view mirror. This has happened 3 or 4 times. This typically happens when the engine is up to normal temperature for awhile, parked for 15-30 minutes with the engine off (going into a store for instance), restarted and out on the road. Upon restart and getting back on the road the stumble/smoke happens. Any help would be greatly appreciated.

Any warning lights on dashboard? CEL light ON? if so you can read codes if you have scanner...

[Arby1028]

Originally Posted by GoRomeo

Any warning lights on dashboard? CEL light ON? if so you can read codes if you have scanner...

No lights at all...I'll go read the codes in a few minutes.

No codes either...just checked. 7E8: Engine and 7EC which I believe are just part of the "reading".

[robprater]

N54? with that mileage, has it ever had the intake valves walnut blasted? Injectors/plugs/coils changed? Does it have a tuner? A lot of things could be happening here. A little black smoke at the start of some spirited driving isn't really abnormal, but if it hesitates then you might have a fuel delivery issue (like HPFP), need a bit of maintenance (plugs, coils, maybe injectors, maybe a walnut blast). Mine did something similar a little while after the JB4. I replaced the spark plugs, pulled the injectors and wound up replacing all 6, and did a walnut blast; it wound up feeling like an entirely different car.

Edit - thought about it some more - maybe you have an injector leaking while the car is sitting that is resulting in fuel accumulation in the cylinder - excess is burned off when you crank and presented as your black smoke. Same malfunctioning injector(s) might be causing the "stumbling" you describe but the misfire might not be a long enough duration to throw a CEL.

[robthewrench]

Sounds like a leaking or bad injector. Black smoke is always a fuel air ratio that has too much fuel. Way too much fuel.

[Arby1028]

Originally Posted by robprater

N54? with that mileage, has it ever had the intake valves walnut blasted? Injectors/plugs/coils changed? Does it have a tuner? A lot of things could be happening here. A little black smoke at the start of some spirited driving isn't really abnormal, but if it hesitates then you might have a fuel delivery issue (like HPFP), need a bit of maintenance (plugs, coils, maybe injectors, maybe a walnut blast). Mine did something similar a little while after the JB4. I replaced the spark plugs, pulled the injectors and wound up replacing all 6, and did a walnut blast; it wound up feeling like an entirely different car.

Edit - thought about it some more - maybe you have an injector leaking while the car is sitting that is resulting in fuel accumulation in the cylinder - excess is burned off when you crank and presented as your black smoke. Same malfunctioning injector(s) might be causing the "stumbling" you describe but the misfire might not be a long enough duration to throw a CEL.

Thanks - N55 motor. Plugs were changed but not coils at about 70k miles. I had a JB4 installed but it started throwing a lot of codes so I removed it. I'll check the injectors.

Originally Posted by robthewrench

Sounds like a leaking or bad injector. Black smoke is always a fuel air ratio that has too much fuel. Way too much fuel.

Thank you - I'll check the injectors and HPFP.

[robprater]

Mine threw codes as well after I installed the JB4, especially when driving rather aggressively. Any weakness in the fuel or ignition are readily identified when you push it a little harder - that's the exact reason I did the injectors and the walnut blast. Typically if your hpfp is weak, injectors/coils/plugs need to be addressed, etc... the tuner will bring them to light (at least it did for me). Addressing the plugs and injectors on my car solved the issue of the CEL with the tuner on. I'm willing to bet it's something similar.

[Arby1028]

Originally Posted by robprater

Mine threw codes as well after I installed the JB4, especially when driving rather aggressively. Any weakness in the fuel or ignition are readily identified when you push it a little harder - that's the exact reason I did the injectors and the walnut blast. Typically if your hpfp is weak, injectors/coils/plugs need to be addressed, etc... the tuner will bring them to light (at least it did for me). Addressing the plugs and injectors on my car solved the issue of the CEL with the tuner on. I'm willing to bet it's something similar.

Thank you!

[mattgu40]

check for vacuum leaks boost solenoid to wastgate accutator. only time i have seen black smoke out of my car was couple years ago when i changed all vacuum hose and left one disconnected..

[Arby1028]

Originally Posted by mattgu40

check for vacuum leaks boost solenoid to wastgate accutator. only time i have seen black smoke out of my car was couple years ago when i changed all vacuum hose and left one disconnected..

Thanks - I haven't touched any vacuum hoses but that doesn't mean one hasn't come loose or is leaking.

[robprater]

Originally Posted by Arby1028

Thanks - I haven't touched any vacuum hoses but that doesn't mean one hasn't come loose or is leaking.

If they have never been changed, might be worthwhile to just change them out too. Another cheap and easy maintenance item to add to the long list we already have. I changed all of mine at about 104K miles. The lines at the vacuum canisters were dried out and cracking, especially on the sides facing the engine. At about 180K, I had to put a new valve cover gasket and valve cover on, so I went ahead and replaced the vacuum lines that connect to the hard plastic lines that run across the top/front of the valve cover while I was working in that vicinity anyway.

There are some good DIY's posted if you are like me and prefer to read about everything in triplicate before diving in.

[Arby1028]

Originally Posted by robprater

Mine threw codes as well after I installed the JB4, especially when driving rather aggressively. Any weakness in the fuel or ignition are readily identified when you push it a little harder - that's the exact reason I did the injectors and the walnut blast. Typically if your hpfp is weak, injectors/coils/plugs need to be addressed, etc... the tuner will bring them to light (at least it did for me). Addressing the plugs and injectors on my car solved the issue of the CEL with the tuner on. I'm willing to bet it's something similar.

What was the cost to replace your injectors? I understand this is a direct injection set-up. Thanks.

(Still having the stumble/black smoke issue)

[Big Mexican Women]

Originally Posted by robthewrench

Sounds like a leaking or bad injector. Black smoke is always a fuel air ratio that has too much fuel. Way too much fuel.

I agree. Note for fuel smell during cold starts and rough running until the engine warms up, decreased MPG, etc

[Arby1028]

Originally Posted by Big Mexican Women

I agree. Note for fuel smell during cold starts and rough running until the engine warms up, decreased MPG, etc

Not getting fuel smell on cold starts and runs smoothly until warmed-up. MPG sucks as it always has in-town!!!

[Arby1028]

Took it to the dealer several weeks ago and they did a full diagnostic. Injectors not leaking, no vacuum leaks, etc. Basically they couldn't find anything except I needed a total of 8 software/firmware updates. I had asked my regular service adviser multiple times (definitely more than 4) when in for other maintenance/oil changes if I had the latest software. Each and every time he said "yes". I very politely complained about this and they waived the diagnostic visit charges (shocker I know!).

On Friday, July 6th I took it in for the software/firmware updates. I haven't driven it very hard since then but plan to this week and will report results.

[PichaDis11]

Originally Posted by Arby1028

Took it to the dealer several weeks ago and they did a full diagnostic. Injectors not leaking, no vacuum leaks, etc. Basically they couldn't find anything except I needed a total of 8 software/firmware updates. I had asked my regular service adviser multiple times (definitely more than 4) when in for other maintenance/oil changes if I had the latest software. Each and every time he said "yes". I very politely complained about this and they waived the diagnostic visit charges (shocker I know!).

On Friday, July 6th I took it in for the software/firmware updates. I haven't driven it very hard since then but plan to this week and will report results.

Anyone else thinks this is just good ole foreplay by the dealer; waiting to slap that work order on the next visit with no lube?