ZD 30 dawes valve and needle valve fitted
Submitted: Sunday, Aug 23, 2009 at 16:24
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Member - Greg T (ACT)
hi gang,
i have finally got around to fitting a dawes valve and needle valve for the Troll.
did it at the
farm so i had a couple of hours driving
home adjusting and seeing how it goes.
fitting:
pretty easy, the hardest part was trying to find a location to put the needle valve for adjusting. i could of put it in the cab, but i like playing with that kind of stuff, so it went under the bonnet on the fire wall.
the dawes valve and needle valve took a bit of playing around to get it to around 10 psi,
how much better is it:
from the 3 hr drive, the boost was more constant (under load while accelerating) and didnt drop off when going up hills which was much easier to drive. i found 5th gear up hills worked much easier than before.
now that this is done, i will block the EGR valve and fit a oil air separator.
getting there
Reply By: Member - John - Sunday, Aug 23, 2009 at 16:47
Sunday, Aug 23, 2009 at 16:47
G'day, you have got me, checked the date etc, not April 1.......... What the hell is a "dawes valve"? Presume it is a turbo boost controller of some description? Await the answer with bated breath.........
AnswerID:
380165
Reply By: Member - Greg T (ACT) - Sunday, Aug 23, 2009 at 21:38
Sunday, Aug 23, 2009 at 21:38
correct.
a dawes valve is basically a ball valve.
connected to the intake pipe (after the turbo) and the vacum hose (which goes to the wastegate to control boost).
when the turbo spools up (crates pressure), the dawes valve (ball valve) is overcome from the pressure created by the turbo and lets + pressure into the vacum hose which intern releases the wastegate and controls the pressure created by the turbo.
and the needle valve controls the rate at which it reaches peak pressure.
on the Patrol ZD30, this is electronically controlled. the problem is when the MAF gets dirty, it (the ECU) thinks there is less air in the air intake and turns the boost up to conteract the inacurate less air.
this is part of why the ZD30 blows up.
so the pin is 1/2 welded in now.
1/2 you ask?
first fix was the new block and internals which has the more oil gallaries, oil capacity, dipstick fix.
2nd fix was the dawes (ball) valve and needle valve, no over boosting now
3rd fix is to block the EGR valve. this valve lets spen exhaust gas into the engine. why does it? enviro controls.. what does it do to the engine? it clogs the intake and pots with crap and makes the engine hotter.
4th and final weld is an oil/air seperator. there is a hose that sends thegas created by the engines internals (oil steam) back into the air intake as a polution control. thus dirtying the MAF sensor and other bits and pices.
AnswerID:
380202
Follow Up By: Member - Greg T (ACT) - Tuesday, Aug 25, 2009 at 17:51
Tuesday, Aug 25, 2009 at 17:51
I owe a lot to the work other guys liike Chaz has put into the references numptys like me can read for the ZD30
FollowupID:
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Reply By: Member - John - Monday, Aug 24, 2009 at 13:46
Monday, Aug 24, 2009 at 13:46
Thanks for the info, I now know why they blow up. I have a 4.2 TD, but will pass on the info to a couple of 3 lt owners I know.
AnswerID:
380268
Reply By: Marny - Monday, Aug 24, 2009 at 18:50
Monday, Aug 24, 2009 at 18:50
Hi all. I have a 2003 d22 navara with the zd30 engine and my question is do these motors have the same problem? I have heard that they have a non variable vane turbo so does the oil vapor effect anything on these motors? Does anything need to be modded on these i.e. EGR valve? THANKS marn
AnswerID:
380307
Follow Up By: Member - Greg T (ACT) - Tuesday, Aug 25, 2009 at 17:35
Tuesday, Aug 25, 2009 at 17:35
Hi Marn,
i dont think the D22 has this problem
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Follow Up By: Marny - Tuesday, Aug 25, 2009 at 21:30
Tuesday, Aug 25, 2009 at 21:30
Thanks for that Greg. I was not sure if i was affected or not.Cheers for the reply. Marn
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