Engine black smoke

[ModlessG]

My 135I smokes on start up and runs rough when cold. When warmed up At full throttle it blows black smoke. You cannot see it from inside the car. My wife was following me yesterday when I took off from a stop.She told me of the smoke. Anyone else have this issue. Thanks

[RaceTime]

I haven't heard of any smoke issues, but I know that there is a large amount of sut around the tailpipes of mine. I thought it was due to the tune. I am interestred to know if there are others with the issue...

[Lester]

Black smoke is unburned fuel. Just imagine what that is doing to your exhaust valves and destroying your catalytic converters. Have you got any tunes or modded downpipes? If not - I would take it into the dealer and have them check it out.

[MadMan77]

+1 to Lester.

Are you running any tunes or piggy-backs?

[BlackjackMulligan]

Sometimes cars blow off stuff through the exhaust on full throttle. If it's just a puff of crap I wouldn't worry about it. If it's continuous black smoke, then yes, I'd address it right away.

[imoz]

Originally Posted by ModlessG

My 135I smokes on start up and runs rough when cold. When warmed up At full throttle it blows black smoke. You cannot see it from inside the car. My wife was following me yesterday when I took off from a stop.She told me of the smoke. Anyone else have this issue. Thanks

My car with ~1100 miles on it now also smokes on start up/idle, but doesn't run rough at all. I haven't seen black smoke while driving, although I've had some people mysteriously honking briefly at me the last few days, so now you've got me wondering.

[ModlessG]

Its completely stock. No mods at all.I couldn't see the smoke only the person following me saw it.I have seen the puff at start up though.

[MadMan77]

Originally Posted by ModlessG

Its completely stock. No mods at all.I couldn't see the smoke only the person following me saw it.I have seen the puff at start up though.

Under hard acceleration, even when stock, you will dump a little fuel out the tail pipes. This would be the black smoke.

Now, the puff of black smoke on start up is a bit odd I think. Do you have any long-crank issues or does it start right up?

[ModlessG]

It has always started right up. I was wondering about the Fuel pump as well. I may just take it in this week and have the dealer check it out.

[MadMan77]

I know the engine runs rich to start but you should not see black smoke on start-up unless you have a leaking fuel injector.

[RPM90]

Originally Posted by ModlessG

My 135I smokes on start up and runs rough when cold. When warmed up At full throttle it blows black smoke. You cannot see it from inside the car. My wife was following me yesterday when I took off from a stop.She told me of the smoke. Anyone else have this issue. Thanks

Are you sure it's "smoke" at startup and not just vapor/water?
Wait, you said it runs rough. That could be a faulty ignition coil, possibly very likely as that would cause a rough idle, and potentially exhaust smoke.

As for the black smoke at WFO throttle, turbo's are notorious for this.
When going WFO the air/fuel ratio goes rich and often people will see this from behind. Depending on the lighting outside this is more or less visible, but it depends on lighting. I notice it on my other turbo cars when the sun is low in the horizon and behind me. WFO and I can see light smoke.
If there is some blue mixed in, you could get some blowby oil in there as well. Many turbo setups collect a good deal of oil especially in the intercooler. So on WFO and high boost some of that oil could get sucked/forced into the combustion chamber and create some smoke.
It's typcially normal and not hurting anything other than very dirty sooty exhaust.