ZD30& NADS(nissan auto destruct system)

[trickydicky]

Been concerned with my 3.0 terrano 2003 as its got the ZD30 patrol engine that has had over boost issues leading to piston failure in no.3 0r no.4 pistons.
Been reading about issues on patrol sites and want to fit a boost gauge and Exhaust temp gauge to define if I have over boost.
do I just fit a T piece in the vacuum pipe going to the turbo and a 12v feed or is it more complicated ?

 

[Sweety]

Boost gauges are easy to fit you just T into the vac pipe on the turbo, feed the pipe for the gauge into the cab & connect it to the gauge & the gauge a 12V feed (back of cig lighter would do) Depending on where you want the gauge you can bring the pipe in by the aircon pipes as there is a drain pipe under them or in via 1 of the grommets next the the main wiring harness on the drivers side bulkhead. No idea about fitting the exhaust temp gauge

 

[trickydicky]

yeah thought the boost would be OK like you said, the exhaust temp needs a tapped hole in exhaust manifold to screw sensor into, I think.
Tried to get boost gauge in Stoke today...easier to find rocking horse dung!
Going to get one off Flea bay

 

[rayf3262]

The VAC pipe on the ZD30 VNT is to regulate the position of the control vanes, it will not show boost pressure.

A better place to pick up the boost pressure from, is after the inter cooler, this is more consistent with the pressure seen at the inlet manifold and may be slightly lower than the IC input.
Note the OEM over-boost sensor is also fitted to the IC.

 

[stinka]

Boost gauge really needs a tap in the inlet manifold as u loose pressure by the time it's all got to the inlet so tapping boost hose gives a false high reading.

Remove inlet manifold drill and tap.

Egt gage needs a tap in the exhaust manifold bit more of a pita but straight forward enough

Just keep your maf clean, I'd stick a new one on just to be sure if its done a few miles, that way you can be sure it's fuelling correctly

Make sure your egr system is in top condition, maybe take the valve off and clean the hell out if it, look in to the effects of blanking it as the shit that they spill in to your manifold is disgusting. When I replaced my leaking inlet manifold and removed my egr valve and blanked it, my manifold had a 1/4 inch thick inner coating of oily shit and soot, I bet yours is the same

 

[firebobby]

There was a thread on here about using a small amount of 2 stroke oil in with the diesel, wondering if this would help keep this part of the engine clear of oily soot deposits :nenau

 

[rayf3262]

There was a thread on here about using a small amount of 2 stroke oil in with the diesel, wondering if this would help keep this part of the engine clear of oily soot deposits :nenau

It may help although the best answer is to stop putting spent exhaust gases back in the inlet path!
However, simply blocking the EGR path on the ZD30 will give rise to a sustained increase in boost pressure, so to reliably block the EGR the maximum boost pressure must be regulated as well.

 

[trickydicky]

thanks for info guys, from what I've read re blanking the EGR can create over boost and people counter this by using a dawes valve to take control of boost manually.
Got wrong end of stick re how to fit boost sensor will do it as per your advice on intercooler pipe.
What's better mechanical or electronic?
What did you use to clean EGR with? how easy is it to remove?

 

[rayf3262]

thanks for info guys, from what I've read re blanking the EGR can create over boost and people counter this by using a dawes valve to take control of boost manually.
Got wrong end of stick re how to fit boost sensor will do it as per your advice on intercooler pipe.
What's better mechanical or electronic?
What did you use to clean EGR with? how easy is it to remove?

I don't think mechanical or electronic really matters, all you need is an indication that the boost pressure is above the acceptable norm, and as long as you can see that either is fine. Though an electronic gauge with an alarm setting would be ideal, would save having to keep an eye on it.

It's the "throttle body" that needs cleaning, it is easy to remove once the IC is off, just be careful not to drop any small parts down the hole!
I cleaned mine with Jizer and elbow grease.
FWIW: the EGR path is directed to only two of the inlet tracts.

 

[Barrbeast]

To be honest bud I wouldn't be worrying overly - the "grenade issues" with the 3.0 engines in the Patrols are mainly a problem on older pre 2002 models due to a combination of overboosting + overfueling due to a dirty MAF + not enough lubrication which then causes severe overheating in pistons 3 & 4 and the resultant BANG. General consensus is that Nissan had fixed the problems with the ZD30 by the time they started fitting it in the Terrano.

Overboosting occurs mainly because of mods like blocking the EGR or fitting larger exhausts and my impression was that the majority of guys with NADS fitted had done some sort of engine mod. Check your MAF regularly and if you think it's dirty try some electrical contact cleaner. Your engine should be of the later design (like mine) with increased oil channels and oil capacity so lube shouldn't be an issue.

Check out the ZD30 DI reference guide:-
http://www.patrol4x4.com/forum/zd30...nce-bible-newbies-start-here-zd30-info-31418/

Personally I think that the problems with the early ZD30's has tainted the rep of what is actually quite a reliable engine - yes it does fail, but nothing is 100% reliable. The only mod I'm currently planning to fit is an oil pressure gauge and then only because I'm fed up with the high pressure sensor going on the fitz and switching on the warning light when there is actually nothing wrong :doh