Puf of blue smoke on cold startup! E84 2010 47 Motor

[dworks]

Hey guys,

When I leave car to sit overnight and start it on colder morning, I get this 1 secund puff of blue smoke and goes away. As well whole day after it starting fine and running fine without any smoke. I have EGR and DPF deleted. Oil level is still on max (cant see any oil consumption). Drove around 3000km. 255 000km on clock.

No codes on engine ecu. Replaced glow plugs relay. Car is running fine, pulling fine, no oil contamination around motor aswell.

Here is the video (4c this morning).

https://drive.google.com/file/d/11az...w?usp=drivesdk

Is this problem? Is dangerous to drive like this? Please let me know your thoughts.

Thank you

[dworks]

Anyone? Please?

[Portly]

Unsure what engine you have, but if it's turbocharged, it may be similar to the issue which plagues the N20 engine, where oil in the feed line leaks past the turbo seals into the compressor, and gets quickly burned off at startup. For the N20 (which you obviously don't have since you mentioned glow plugs), BMW created a different oil feed line with a check valve in it, which is supposed to keep the oil from leaking down into the turbo unless the engine is running (and the oil pressure overcomes the check valve.)

I have no idea how successful that fix is - mine typically generates a small puff of smoke if it has sat for more than a couple days, but it's been doing that for the last 50,000+ miles (80,000+ kilometers) and hasn't gotten worse, so I've not bothered to do anything about it.

I personally don't have any concerns about driving my car like this - the amount of oil that's leaking past is tiny, and doesn't seem to indicate that a more extreme seal failure is likely.

[dworks]

Originally Posted by Portly

Unsure what engine you have, but if it's turbocharged, it may be similar to the issue which plagues the N20 engine, where oil in the feed line leaks past the turbo seals into the compressor, and gets quickly burned off at startup. For the N20 (which you obviously don't have since you mentioned glow plugs), BMW created a different oil feed line with a check valve in it, which is supposed to keep the oil from leaking down into the turbo unless the engine is running (and the oil pressure overcomes the check valve.)

I have no idea how successful that fix is - mine typically generates a small puff of smoke if it has sat for more than a couple days, but it's been doing that for the last 50,000+ miles (80,000+ kilometers) and hasn't gotten worse, so I've not bothered to do anything about it.

I personally don't have any concerns about driving my car like this - the amount of oil that's leaking past is tiny, and doesn't seem to indicate that a more extreme seal failure is likely.

Thank you for your anwer!

Engine is N4720C. So yeah, only small pufs at start. Seems that is less noticable when its warmer outside. I have attached video so you can check it. So after all, you think this is not much a problem right?

Have not seen any oil consumption in 3000km.

[maxwmiller]

Can you rule out having incomplete combustion at startup? With an aging, double-deleted Diesel motor, I could see how the engine may start in a rich condition, and have a small "coal roll".

No oil consumption is good though. Build sounds sweet!