excessive oil in intake

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dennis_lambert
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excessive oil in intake

Post by dennis_lambert »

My poor L300 has been having an increasingly difficult time starting and when it finally does its blowing out smoke like crazy! :o
When I pulled the intake hose off it was full of oil.I was suspecting its been pulling oil from the pcv hose on the top of the valve cover.
To me it seems like too much oil for bad valve seals.
There is no oil in coolant and no coolant in oil....
Could it be the piston rings?Too much blow by overpressurizing the oil system?
Any thoughts would be greatly appreciated!
Thanks!
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Firesong
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excessive oil in intake

Post by Firesong »

Recently with if being this cold out I would bet your l300 hasn't been warming up enough. Hard starts in the cold equal smoke plus not getting warmed up = poor diesel to air ratios. Blowing unburnt diesel out the back end. You may have a glow plug not doing its job too. That would be where I would look on my old l300 first.
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Firesong
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excessive oil in intake

Post by Firesong »

lol. For some reason I thought you were from the prairies. My bad. Still how are the glow plugs?
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Re: excessive oil in intake

Post by thedjjack »

Until you figure it out put a catch can on the oil so you do not end up with a runaway diesel...

Runaway diesel is when it starts running off the oil in the intake and you cannot physically stop the engine it just revs unstoppable until it throws a rod or seizes... very scary....

Especially automatics cannot be stopped..
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Re: excessive oil in intake

Post by konadog »

thedjjack wrote:Until you figure it out put a catch can on the oil so you do not end up with a runaway diesel...

Runaway diesel is when it starts running off the oil in the intake and you cannot physically stop the engine it just revs unstoppable until it throws a rod or seizes... very scary....

Especially automatics cannot be stopped..
Disconnect the battery?
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Re: excessive oil in intake

Post by thedjjack »

Nope runaway is using typically the crankcase oil as the fuel..

Being a diesel no spark just compression to light the fuel so if it not using diesel through the injector pump it is near impossible to stop...

youtube runaway diesel: http://www.youtube.com/watch?v=hOQ66cZaPb4

The only way to stop them is standard transmission or put something (usually a wood block) into the intake or a CO2 fire extinguisher
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Re: excessive oil in intake

Post by dennis_lambert »

Thanks for the info!
It did run away once all ready!
I had to quickly pop the clutch and stall it.
Your right it was scary!
I did not know why it did it until you told me....thanks.
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Re: excessive oil in intake

Post by thedjjack »

It could be a blown head gasket into an oil passage as well.

Leak down test is the best test

Put cylinder at top dead centre with valves closed
then you add compressed air through the glow plug port (spark plug on gas motor)
then you watch how quick the pressure is lost and listen at intake, exhaust, crankcase for the leak
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Re: excessive oil in intake

Post by Erich »

To stop a runaway diesel would removing the glow plugs work? Eliminate compression and it won't ignite the fuel.
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Re: excessive oil in intake

Post by Mr. Flibble »

Erich wrote:To stop a runaway diesel would removing the glow plugs work? Eliminate compression and it won't ignite the fuel.
That would work, but you would be crazy to want to get that close to the engine head while it was busy running away.

Getting hit in the face with bits of engine is generally not pleasant.

Your best bet is to block the air intake as it is the fastest solution you have that is most likely to work.
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excessive oil in intake

Post by Firesong »

Glow plug removal would not work. Once warm the engine doesn't require them.
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Re: excessive oil in intake

Post by Mr. Flibble »

Firesong wrote:Glow plug removal would not work. Once warm the engine doesn't require them.
Sure it would.

Without glowplugs there is no compression in a cylinder, thus no ignition and the runaway stops.

Taking out the glowplugs would take too long though, and put your face right over the engine head. Not a great idea.
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excessive oil in intake

Post by Firesong »

Glow plugs warm the system up. Once it's running the diesel fires due to compression not ignition from glow plugs.
They will provide an afterglow for a few minutes but after that their job is done. Check ngk's site for more info.

http://www.ngk.de/en/technology-in-deta ... el-engine/
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excessive oil in intake

Post by Firesong »

Hopefully your not suggesting pulling plugs while it's running to fire the compression out the glow plug hole? Can you say bullet to the head?
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Re: excessive oil in intake

Post by yojimbo »

A diesel always fires from compression ignition. You dont even need glow plugs to start a diesel, just the right conditions, glowplugs help provide them, but I've seen diesels start without them in even UK weather.
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