BMW F11 - what is this smoke coming from my engine?

BMW F11 - what is this smoke coming from my engine?

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Discussion

SilliousSodus

Original Poster:

7 posts

1 month

Saturday 12th October
quotequote all
Hi all,

I had a really scary moment with my 520D today, having just pulled into my driveway after a short journey.

There was a sudden strong smell of burning plastic and thin smoke started to appear in the cabin. When I realised it was coming from the front of the car - big plumes of smoke coming up from under the bonnet - I lifted the bonnet fully expected to see a fire.

I recorded the smoke on my phone and put it up on YouTube. As I'm a new member, I'm not yet allowed to post links - just do a YouTube search for the video ID "Pssn3fG25pQ" or the video description "Scary smoke coming from BMW F11 engine compartment".

Even though you can see a leak in the engine compartment, it didn't smell like burning oil.

One thing I didn't notice at the time, but you can see it in the recording, is that the smoke wasn't continuous - it came in waves.

Does anyone know what might have happened here? I don't want to drive this car again or put my family into it until I'm sure it's safe to do so.



SilliousSodus

Original Poster:

7 posts

1 month

Saturday 12th October
quotequote all
Pehaps related -

This car has been into the dealer twice as part of the EGR cooler recall a couple of years ago. So far as I know, the original EGR was replaced.

Yesterday, there was a check engine light and I got the following fault codes from a reader:



258700 Exhaust gas pressure sensor, diesel particulate filter, signal: Too low

290900 Air mass system: Measured air mass too high (Exhaust gas pressure sensor before turbine faulty (in conjunction with the fault codes 27B900 and/or 4C83 and/or 28DE00 and/or 4990)).

28DE00 Exhaust backpressure sensor before turbocharger, signal: Dynamics implausible

2C2200 Coolant temperature sensor upstream of low temperature EGR cooler, coolant
temperature, signals: implausible with each other

Scrump

22,935 posts

165 months

Saturday 12th October
quotequote all
I can’t hear any sound on your video, not sure if it is meant to have some.
Smoke looks to me like something burning off a hot manifold or engine, your video just before the 1minute mark shows a shiny bolt head with a nut which seems to be in an area wet with something (likely to be oil but could be diesel). If this is the area the smoke is coming from then I would be trying to find out why it wet down there.
Keep us updated with findings.

TooLateForAName

4,838 posts

191 months

Saturday 12th October
quotequote all
take the engine cover off - will help you see.

did the smoke smell of oil/diesel/coolant?


Olivergt

1,645 posts

88 months

Sunday 13th October
quotequote all
As you say, the smoke wax coming in waves, which is clearly visible in your video.

As others have mentioned, get the engine cover off, shouldn't be too difficult, you'll be able to get a better view of what is going on.

Hopefully just the rocker cover gasket or a simple split pipe somewhere.

Good luck and keep us updated. It's always good to get a resolution in these types of threads as it helps others who may experience the same symptoms.

paintman

7,765 posts

197 months

Sunday 13th October
quotequote all
Engine cover off.

Have a thorough look around the engine t make sure something hasn't found its way into the engine bay, such as a plastic bag - which may have been picked up from the road - & has come into contact with something hot.

Are these susceptible to copper sealing rings on the diesel injectors failing & allowing blowby?
I know some Mercedes are & my own Sprinter had what is very common & referred to as 'the black death'. That looked like smoke pulsing from under the plastic engine cover.
The failed seal allows combustion gases incl partly burnt diesel to exit the cylinder & blow past the side of the injector body - easily seen once you can see the injectors.
A quick google & ebay pics leads me to believe that the injectors & the copper sealing washers they use are very similar.

Edited by paintman on Sunday 13th October 11:18

silentbrown

9,351 posts

123 months

Sunday 13th October
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E-bmw

9,969 posts

159 months

Sunday 13th October
quotequote all
TooLateForAName said:
take the engine cover off - will help you see.

did the smoke smell of oil/diesel/coolant?
This, the "smoke coming in waves" could just be a drop of something dripping onto a hot surface & then smoking off, but until you get the cover off you will see nothing.

Camsnowflake

17 posts

1 month

Sunday 13th October
quotequote all
Thanks for the video,
Looks as though the smoke is emanating from very low down on the chassis, nothing to do with engine IMO

SilliousSodus

Original Poster:

7 posts

1 month

Sunday 13th October
quotequote all
Thanks @silentbrown for linking the video.

Scrump

22,935 posts

165 months

Sunday 13th October
quotequote all
Camsnowflake said:
Thanks for the video,
Looks as though the smoke is emanating from very low down on the chassis, nothing to do with engine IMO
If oil or diesel is leaking from the engine it would drip or run down onto the chassis.

SilliousSodus

Original Poster:

7 posts

1 month

Sunday 13th October
quotequote all
Thanks for the input all.

I'll definitely take the cover off to get a better look.

I was thinking last night that maybe it was some weird DPF regen thing and that I should bring it for a quick run on the mortorway, but maybe I should hold off on that until I know more?

Another thing worth mentioning, now that I remember it -
When I was reading the fault codes the day prior, I had the car idling for maybe 15 minutes in total. During this I noticed an unusual amount of white smoke rising from the rear exhaust pipe, but I thought nothing much of it. Maybe what I experienced in the video was excess diesel burning off?

Jakg

3,602 posts

175 months

Sunday 13th October
quotequote all
My guess is an oil leak, probably from a failed valve cover or gasket, which is leaking oil onto the exhaust and burning off.
The DPF specifically gets hot, especially if it's partially blocked (which the backpressure fault suggests).
Common on N57 engines, oil leaks onto the exhaust flexi specifically.

Does it smell of burning oil? That's the giveaway.

E-bmw

9,969 posts

159 months

Sunday 13th October
quotequote all
SilliousSodus said:
When I was reading the fault codes the day prior, I had the car idling for maybe 15 minutes in total. During this I noticed an unusual amount of white smoke rising from the rear exhaust pipe,
Most likely water vapour rather than smoke, especially if it was just started.

Of course it could be other things & may be significant but commonly it is just water vapour.

paintman

7,765 posts

197 months

Sunday 13th October
quotequote all
E-bmw said:
SilliousSodus said:
When I was reading the fault codes the day prior, I had the car idling for maybe 15 minutes in total. During this I noticed an unusual amount of white smoke rising from the rear exhaust pipe,
Most likely water vapour rather than smoke, especially if it was just started.

Of course it could be other things & may be significant but commonly it is just water vapour.
Especially now the weather's getting colder.

Camsnowflake

17 posts

1 month

Sunday 13th October
quotequote all
Is the windscreen wash reservoir leaking?

SilliousSodus

Original Poster:

7 posts

1 month

Sunday 13th October
quotequote all
Camsnowflake said:
Is the windscreen wash reservoir leaking?
No, not that I can see.

essayer

9,616 posts

201 months

Sunday 13th October
quotequote all
This is exactly how mine looked when the valve cover gasket failed. Mine was an older car but same issue, I assume: Oil drips out and down into hot components. Easy fix.

SilliousSodus

Original Poster:

7 posts

1 month

Sunday 13th October
quotequote all
Just back from a half hour roundtrip on the motorway. I can't reproduce the problem.

With the engine cover off and looking around with a flashlight, there are definitely signs of oil leakage and build-up towards the back and driver-side of the engine- but nothing obviously fresh.

It's a bit of a mystery.

Edited by SilliousSodus on Sunday 13th October 16:37

silentbrown

9,351 posts

123 months

Sunday 13th October
quotequote all
DPF regen? Stuff gets extremely hot while that's in progress.