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smoke from rocker breather

Posted: Thu Feb 12, 2009 9:16 pm
by Benny Jahmin
i have got a 92 patrol with td 42 with dyna turbo and 360,000 on the clock
only had it 6 months ... when i gave it a service over christmas i took the rocker cover off and done the tappets too ... i noticed oil in the intake before the turbo .. so i cleaned it up and have done a couple thou since .. just as much oil there again .. took off the breather from the rocker cover and seems to be pretty smokey ..
from what i know that is a general indication of the health of the engine and am a bit worried about it.
is there a way of telling wethere its a bottom end problem or the head??

Posted: Thu Feb 12, 2009 9:23 pm
by SIMMO84
How much? It is normal for some oil in the intake. Unless there is as much blow by coming out of your engine as your exhaust i wouldnt worry too much.
PS the smoke is combustion gasses coming past the pistons.

Posted: Fri Feb 13, 2009 6:18 am
by BundyRumandCoke
A degree of smoke is normal. In the old days it would be vented to atmosphere, (have a look at early Holden red or grey motors) As anti pollution laws became more stringent, these gases/smoke and oily residue were redirected back into intake manifolds, so they would be burnt during the normal combustion process. The vacuum in the manifold sucked the gases past the PCV valve.

The question here is, is it too smokey?

Posted: Fri Feb 13, 2009 6:55 pm
by Benny Jahmin
yea that is the question ... how much smoke is too much
there is no smoke out the exhaust when idiling but noticeable white smoke coming out the breather hose
if it is a problem what explainatins are there .. eg valves leaking or could it be bottom end??

Posted: Fri Feb 13, 2009 8:06 pm
by SIMMO84
Smoke out of your breather IS BLOW BY, combustion gasses coming past the pistons ( as the pistons, rings wear more comes past), new engines do it, old engins do it more, if it runs/starts no worries you dont have compression problems. If you got money to burn waste it on rebuilding your motor.

Posted: Sat Feb 14, 2009 9:39 am
by Jacked
the best way that will give you an indication is to block pcv hose and take the oil cap off and feel for air "puff's" out the rocker cover, smoke can just come from over heated/ burning oil as well with in a turbo engine is.

most engines have none to very little air trying to escape. if it blows quite a bit past indactes wear on all cylinders, if it "puffs" like a steam train indacates wear on a single cylinder

Posted: Sat Feb 14, 2009 5:48 pm
by Benny Jahmin
i took the oil cap off and blocked the breather hose .. was still smokey and when i put my hand over it i couldnt hold it on for more than 3 to 4 seconds before there was too much pressure

should i be looking for a new donk??

Posted: Sat Feb 14, 2009 6:24 pm
by SIMMO84
Benny Jahmin wrote:i took the oil cap off and blocked the breather hose .. was still smokey and when i put my hand over it i couldnt hold it on for more than 3 to 4 seconds before there was too much pressure

should i be looking for a new donk??
If it actually pushed your hand off then yes you would have problems.
I have never ever even heard of that happening. (unless like other people have said it is puffing then yes be worried)
Like i said if it starts/runs ok it will probably go for a long time yet.
Keep an eye open for a good runner if your worried but i wouldnt be too worried.
Im a mechanic and trust me when i say i have never seen a diesel not run because it has worn out something else always craps itself first.

Posted: Sat Feb 14, 2009 7:03 pm
by Benny Jahmin
cheers simmo
i figure its good till it stops .. just sucks i dont know how long till then and where i will be
when it its about 2900rpm i get a vibration throo the accelerator pedal and goes at 3000rpm???
will a td42t bolt strait in

Posted: Sat Feb 14, 2009 7:16 pm
by BundyRumandCoke
One of my previous DL50 donks in my Rocky would smoke like crazy at lights, lets talk smoke screen, it was embarrasing at lights. Crankcase pressure is exhausted to atmosphere with them. When it was eventually pulled down, 2 crowns were cracked. But it was still running, and reasonably well.

Posted: Sat Feb 14, 2009 7:31 pm
by SIMMO84
Benny Jahmin wrote:cheers simmo
i figure its good till it stops .. just sucks i dont know how long till then and where i will be
when it its about 2900rpm i get a vibration throo the accelerator pedal and goes at 3000rpm???
will a td42t bolt strait in
As far as i know there the same block so yes, internals will be the only difference but probably be dissapionted the factory turbo is probably more tame than yours is now.

Posted: Sun Feb 15, 2009 11:18 am
by jeep97tj
Dont worrie about crankcase pressure it dosent mean shit, as every engine is different. If your worried do a compression test on it, but if it starts ok and drives ok more than likely u have nothing to worrie about.

I have a 5L hilux, If u sit the cap over the hole it bounces and rattles around on top. Did a compression test on it and was perfect.

PS I'm a diesel mechanic.

Posted: Sun Feb 15, 2009 3:00 pm
by hiy6o
Yep the compression test is the best way to find out whats what The engine does displace air just by moving the pistons up and down , when the piston is forced down on ignition the air under it has to go somewhere, which could be what your feeling at the cap. Also no piston ring seals perfectly so some compression is going to get by , just how much determines how good the motor is.

Posted: Sun Feb 15, 2009 10:22 pm
by Benny Jahmin
so compression test is the next thing
if that fails i have found a td42t short block with 150000km on it
is $2000 reasonable if in good order??

.. will everything else from the td42 block bolt on .. i know the starter is diferent .. what about the head and maniolds .. injector pump .. water pump .. ???

Posted: Mon Feb 16, 2009 9:24 am
by Jacked
just keep driving it.