Bmw white smoke on startup then stops after accelerating

[Kpwright01]

Hi all, i have a bmw 520d. When i leave the car over night or when it has been sat for a while when im at work i start it and it has a misfire with lots of white smoke. I accelerate the engine once or twice when and the smoke clears and does not come back until the car has been off and cooled down for a while. I have changed the glow plugs this had no affect maybe even made it slightly worse in the morning. Please help

[328 Power 04]

Does the white smoke have a diesel smell or an engine oil smell?

Not all 520d are alike, so you will have to help us with details.

[Kpwright01]

I think its more of a diesel smell but not 100% sure. Its defintly got a chemical type smell. Its the e60 model n47 engine 2.0l 177bhp version

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I have checked oil filler cap there is no oil/water mixture gunk. No warnings on the idrive and no fault codes when i plug in my diagnostic scanner.

[325bob]

I think its more of a diesel smell but not 100% sure. Its defintly got a chemical type smell. Its the e60 model n47 engine 2.0l 177bhp version

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I have checked oil filler cap there is no oil/water mixture gunk. No warnings on the idrive and no fault codes when i plug in my diagnostic scanner.

"white smoke" is a classic head gasket seepage clue, burned coolant/water, seals as engine warms and unseals when cooled, relieve the system pressure after next drive,see if less smoke on next startup.

[328 Power 04]

In a diesel it could easily be unburned diesel vapor too, especially if it stops so quickly.

I would use diagnostics to find out which cylinder/s are rough and pull the injectors. Is check engine light on?

[Kpwright01]

"white smoke" is a classic head gasket seepage clue, burned coolant/water, seals as engine warms and unseals when cooled, relieve the system pressure after next drive,see if less smoke on next startup.

Hi thanks for the reply. I relieved pressure last night the smoke is the same this morning. No mayo type stuff in the oil fill cap but i did see a tiny stream of bubbles in coolant reservoir. Would the car not run weird if head gasket was blowing

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In a diesel it could easily be unburned diesel vapor too, especially if it stops so quickly.

I would use diagnostics to find out which cylinder/s are rough and pull the injectors. Is check engine light on?

Hi thanks for the reply there is no check engine light and no faults on the idrive car runs great after the smoke has cleared

[325bob]

Hi thanks for the reply. I relieved pressure last night the smoke is the same this morning. No mayo type stuff in the oil fill cap but i did see a tiny stream of bubbles in coolant reservoir. Would the car not run weird if head gasket was blowing

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Hi thanks for the reply there is no check engine light and no faults on the idrive car runs great after the smoke has cleared

bubbles in the tank is another classic HG clue, you might get lucky with a can of Bars leak, I've seen it work maybe 1/3 of the time, retorqueing head bolts can help..

[Kpwright01]

bubbles in the tank is another classic HG clue, you might get lucky with a can of Bars leak, I've seen it work maybe 1/3 of the time, retorqueing head bolts can help..

Thank you for the reply, it is going to a garage today to get a head gasket diagnostics. The thought of putting a permanent gasket sealant into my engine scares me too much i have a feeling it will block holes that shouldnt be blocked. Whats your thoughts on this?

[MarcoZandrini]

That head gasket sealer in scan will clog up the cooling system. Don’t do it.

[Kpwright01]

That head gasket sealer in scan will clog up the cooling system. Don’t do it.

Thats what i though not worth the risk as i actually want to keep the car.

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Went to the garage he seems to think ita not gaskets but turbo related. Wouldnt it constantly smoke if the seals was on the way out? After more research i am leaning towards bad valve stem seals any thoughts on this

[Kpwright01]

I changed the oil and filter over the weekend. When i was under the car i noticed oil and soot running down the pipe coming from the turbo. Does that mean that i have an oil leak in the turbo?

[MarcoZandrini]

Yup! The turbo’s oil seals are bad. Replace the turbo with a rebuilt unit.

[Kpwright01]

Yup! The turbo’s oil seals are bad. Replace the turbo with a rebuilt unit.

Wouldnt it constantly smoke if the turbo is leaking oil? It only smokes in the morning or when left for a few hours to cool. Smoke goes away as soon as i drive away