Lots of blue smoke! 😫

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Bsim9751
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Lots of blue smoke! 😫

Post by Bsim9751 »

I’ve got a van with the xud engine in and it’s started to smoke, a lot! Clouds of blue smoke. And a big oil leak from the rocker cover. I guess these are related as they started around the same time. I was told that the smoke would be oil seals in the turbo so I changed that. It still smokes. Any ideas? Could it be a blocked breather?

ekjdm14
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Re: Lots of blue smoke! 😫

Post by ekjdm14 »

Possibly yes, but could be a few other things too. I'd expect a blocked breather to also push the dipstick out & in bad cases push the front and rear crank seals too. Is it definitely coming out of the exhaust and not leaked oil from the rocker cover burning off on the manifold/downpipe?

I suppose as a check at this stage i would remove the breather pipe from the rocker cover and see if it helps the smoke (also note how much it breathes, as it could possibly be worn/damaged piston rings if it's rapidly pushing lots of air/fumes out of the breather). Do check the oil level too, make sure it's not excessively high due to coolant (from HG or oil cooler) or fuel (leaking injector).

Also just a note to be on-guard if it's burning oil, if it is burning inside the combustion chamber then there is the potential for a runaway where you cannot shut off the engine either by switch or stop lever nor by putting in gear and stalling it (The power/torque a runaway diesel makes is incredible, far higher than it's normal rating! you'll only burn out the clutch or break something in the drivetrain).

In this situation the only 3 ways to stop it are, either block the air intake pipe with a board and smother it out, my preferred method of having a CO2 fire extinguisher handy and setting that off down the intake until it stops (that way i don't have to remove the air filter housing or dismantle anything, just make sure i know where the air intake is drawing from), or the third way is to stand well back and wait for it to lock up or throw a rod (extinguisher maybe handy for this method too!).

Don't wish to worry you unduly, but it happens and is scary as all hell when it does so just be aware and don't let it catch you unprepared.

Bsim9751
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Re: Lots of blue smoke! 😫

Post by Bsim9751 »

Wow ok. Thanks. Sounds pretty worrying. The smoke is definitely coming out of the exhaust. It’s had a progressively worsening oil leak for a few weeks then suddenly the blue smoke came along. I’ll try the breather tomorrow. Is it the pipe from the oil filler neck to the intake piping? Or is there another one?
Thanks

ekjdm14
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Re: Lots of blue smoke! 😫

Post by ekjdm14 »

IIRC there's one from the oil filler to air intake as you say & one from the rocker cover to the oil filler too, although you'd get a fair idea of how much blow by there is from just removing the oil filler cap itself to be fair. Might be easier to do that than wrestle with oil-hardened rubber, but if you do then yes I'd go for where it connects to the air filter/intake as that's likely the easiest to remove (also check inside the air filter housing/intake duct, if its dumping oil in there from blow by the you could eke a last few miles out more safely by running the breather into a catch tank instead of the intake).

Like i say, don't wish to scare you unduly but having witnessed a runaway first hand i know how much i panicked not knowing what to do. Had i known, would still have been a heart-starter for sure but at least not full on panic stations.

Hopefully it's something simple and easy to fix, but it doesn't sound great for the engine i must admit.

Gibbo2286
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Re: Lots of blue smoke! 😫

Post by Gibbo2286 »

ekjdm14 wrote:
15 Jan 2020, 20:26
Possibly yes, but could be a few other things too. I'd expect a blocked breather to also push the dipstick out & in bad cases push the front and rear crank seals too. Is it definitely coming out of the exhaust and not leaked oil from the rocker cover burning off on the manifold/downpipe?

I suppose as a check at this stage i would remove the breather pipe from the rocker cover and see if it helps the smoke (also note how much it breathes, as it could possibly be worn/damaged piston rings if it's rapidly pushing lots of air/fumes out of the breather). Do check the oil level too, make sure it's not excessively high due to coolant (from HG or oil cooler) or fuel (leaking injector).

Also just a note to be on-guard if it's burning oil, if it is burning inside the combustion chamber then there is the potential for a runaway where you cannot shut off the engine either by switch or stop lever nor by putting in gear and stalling it (The power/torque a runaway diesel makes is incredible, far higher than it's normal rating! you'll only burn out the clutch or break something in the drivetrain).

In this situation the only 3 ways to stop it are, either block the air intake pipe with a board and smother it out, my preferred method of having a CO2 fire extinguisher handy and setting that off down the intake until it stops (that way i don't have to remove the air filter housing or dismantle anything, just make sure i know where the air intake is drawing from), or the third way is to stand well back and wait for it to lock up or throw a rod (extinguisher maybe handy for this method too!).

Don't wish to worry you unduly, but it happens and is scary as all hell when it does so just be aware and don't let it catch you unprepared.


I was told about that back in 1953 when I first started working on diesels but in all my almost 70 years at it since I've never seen it actually happen.

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Stickyfinger
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Re: Lots of blue smoke! 😫

Post by Stickyfinger »

Last edited by myglaren on 16 Jan 2020, 13:02, edited 1 time in total.
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Michel
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Re: Lots of blue smoke! 😫

Post by Michel »

I've seen it happen once, 25 years ago in a Fiat Uno diesel. Friend driving, changed down into 2nd entering a bend and it must have spat engine oil into the air filter as it went into runaway and we shat ourselves. Managed to stall it and call the AA, and the AA man explained about runaway. Car was fine until my mate sold it a few years later.

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Stickyfinger
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Re: Lots of blue smoke! 😫

Post by Stickyfinger »

Yep, stall it QUICK or block the Air Intake

ekjdm14
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Re: Lots of blue smoke! 😫

Post by ekjdm14 »

Yes it's an unlikely thing (I've driven an Escort TD that was producing a real smokescreen, to get it back to where i was stripping it & that never so much as hiccupped) but if/when it does, it's not something you want happening without being forewarned and prepared. Maybe I'm just (un?)lucky to have witnessed a Mercedes go nuts, was pretty spectacular though if you enjoy a smoke show!