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Smoke at start up

Posted: Wed Jan 28, 2009 1:29 pm
by DASH123
Hi all,

I have a 2000 model 3L Diesel Hilux that is blowing quite a large puff (1-2 secs) of light blue smoke on start up but then it completely stops. It doesn't blow any smoke under load. Oh and the longer that it hasn't been run the longer the smoke takes to clear.

I have been told it may be unburnt oil finding its way back into the engine via the breather hose in the top of the rocker cover?

Also possibly Headgasket, valve seals, leaking injector, rings, etc

Any ideas as to how I could pin point what could be causing this?

Thanks in advance

Posted: Wed Jan 28, 2009 3:59 pm
by joel HJ60
Blue smoke is oil being burnt in the combustion chamber.

It may be your valve stem seals or your head gasket. Judging by the fact the longer you leave it the more blue smoke it puffs I would say it's valve stems. I.E. leaving it more time for the oil to dribble passed the valves. I'm not sure if they can be replaced with the head still ON, I have never had the head off a 5L.

How bad do you want it fixed and how badly do you want to not pull the head?

Posted: Wed Jan 28, 2009 7:08 pm
by SIMMO84
Ive heard of a way of doing valve stem seals without taking the head off,
you need to make up a fitting by finding a pipe fitting that will screw into the glow plug hole and braize a nitto fitting onto the other end so you can plug an air line onto it. This will hold the valves from falling into the motor (have the piston on TDC just incase) then you replace the valve seals as normal.

Posted: Thu Jan 29, 2009 7:05 am
by DASH123
Cheers for the info guys...but I was told that it probably wasn't the valve stem seals because it doesn't blow any smoke under load does that sound true?

Posted: Thu Jan 29, 2009 6:56 pm
by SIMMO84
Not really

Posted: Thu Jan 29, 2009 8:49 pm
by craz3d
Nope it'll only be on startup, cause the oil leaks through the stems when it's off, and it burns the oil in those first few seconds. After it's cleared out, there's nothing there to burn and the oil doesn't really have any noticeable affect cause it's leaking through so slowly. It'll be the stem seals, they're pretty cheap to get a hold of, just need to find a way to change them, usually involves taking the head off though.

Posted: Fri Jan 30, 2009 7:02 am
by mike_nofx
Is it a turbo, and if yes, could it leak in through the turbo while sitting?

My 100 series blows a puff of smoke at start up, then goes away like yours. Pretty much every diesel i've driven (work trucks and utes mainly) all seem to blow a puff on start up.

Mike