Thread: ZD30 engines

Right, the latest in the saga...

Today, took it for a test drive with the upstream pyrometer fitted.

This thing is running SO much fuel through it, I'm suspecting the MAF sensor.

I got 626degrees climbing a moderate hill, partial throttle loads, in drive. This temp was reached in less than a km.

It doesn't smoke, and has adequate power, so IF the MAF is ok etc, then this must be the reason they have melted pistons and blown turbos. I'm not game to hook up his 20ft caravan and test drive it until the new engine has a few more km under its belt, but I'm stunned at how high the EGT's are!!!


JC

Originally Posted by justinc

Right, the latest in the saga...

Today, took it for a test drive with the upstream pyrometer fitted.

This thing is running SO much fuel through it, I'm suspecting the MAF sensor.

I got 626degrees climbing a moderate hill, partial throttle loads, in drive. This temp was reached in less than a km.

It doesn't smoke, and has adequate power, so IF the MAF is ok etc, then this must be the reason they have melted pistons and blown turbos. I'm not game to hook up his 20ft caravan and test drive it until the new engine has a few more km under its belt, but I'm stunned at how high the EGT's are!!!



JC

Some of the old 4D56T Mitsu's can hit 720 ex factory Thats post turbo
The ZD30 around here are only dying from bad fuel.
Will be interesting what you find

Tony

There was a few thread on the Patrol4x4.com forum about them, but one in particular was getting every 3.0 owners history of problems. There seemed to be more issues with Air Flow sensors than anything else, but quite a few did go bang and some a second time after repair by nissan.

Originally Nissan did replace the failed units with new short motors however i beleive that they now simply rebuild them. That is if you can get them to come to the party on it. You will still be charged for labour and odds and sods though.

They were supposed to have resolved the issue in the later models, but there are still reports of them going bang.

If you check used vehicles you will find quite a few with new or rebuilt engines. Overall they are considerably cheaper than the other models, possibly due to their reputation.

I think the biggest issue with them is that there is no one answer as to why they fail. No one seems to have a definative reason for it, and Nissan dont really acknowledge it as a fault (hence no recall). Without knowing exactly why this happens, its hard to fix it so it does not do it again.

Would I buy one? No simply because you just dont know when or if it will let go.

Originally Posted by Rangier Rover

Some of the old 4D56T Mitsu's can hit 720 ex factory Thats post turbo
The ZD30 around here are only dying from bad fuel.
Will be interesting what you find

Tony

Interesting I had two 4D56T's and although slow, never had a single issue with them, nor has my mate who bought mine off me (yes, it was good enough to sell to a mate!).

I just think it's a shame that the execution of what Nissan envisaged has been such a disappointment. The concept of a large 4WD being adequately powered by a comparatively small (and economical) motor.

I haven't looked at figures or compared weights with the Patrol, but given the Pajero Di-d was hailed as a "rocket ship" when launched, I haven't heard of them going bang, so what did they do right?
Cheers
Mike

Originally Posted by justinc

Right, the latest in the saga...

Today, took it for a test drive with the upstream pyrometer fitted.

This thing is running SO much fuel through it, I'm suspecting the MAF sensor.

I got 626degrees climbing a moderate hill, partial throttle loads, in drive. This temp was reached in less than a km.

It doesn't smoke, and has adequate power, so IF the MAF is ok etc, then this must be the reason they have melted pistons and blown turbos. I'm not game to hook up his 20ft caravan and test drive it until the new engine has a few more km under its belt, but I'm stunned at how high the EGT's are!!!


JC

626 isn't that bad.
But is the turbo on that one variable vane and controlled by the computer (via the MAF sensor)?

Originally Posted by Dougal

626 isn't that bad.
But is the turbo on that one variable vane and controlled by the computer (via the MAF sensor)?

Hi Dougal,

626 was wrong, the pyro tell tale tells me 676
I mentioned this as excessive, because I wasn't even CLOSE to working it hard, not to mention he tows a 20foot caravan with it! As it is a new engine, I'm not game to push it hard with those EGT's.

Yes, it IS controlled by a MAF sensor, and today I am trying a new one to compare

JC

Can I ask a mechanical question? Given that I'm an IT person?

Why don't chipped td5's have these issues? I've not seen any meaningful analysis that suggests that chipping a td5 results in more issues than running them standard?

We did have a poll a while ago that did show a slight correlation between chipped td5's and exhaust gaskets but it did not take into account the total numbers of chipped td5's so was essentially meaningless. It's my impression that at least 50% of td5 posters on this board have had the upgrade.

All the td5 issues seem to be correlated to poor maintenance rather than usage. (perhaps the early ones did have some issues that were fixed later)

Looking over some of the other forums no one has made a proper study as in EGT,boost pressure etc to find out whats going on.JC if that thing is pulling 676 degree's when not working that doesn't sound good compared with a Tdi which is only around 300 at similar conditions.Put the van on and drive up a hill,see how hot it gets. Pat