Want to buy used 3.0 L

[Robbo]

G day all, i am currentley looking at buying a used Gu 3.o L GU. I have heard there was some problems with some of the earley models. I would appreciate some info on this and what to look out for when buying.

[Maxhead]

There's been a few issues with the pre 2003 3.0l motors but they seem to be a lot better after 03. I'm not that mechanical so can't help you there but I would check the service history and make sure it's been serviced regularly.
Take it to a diesel mechanic you can trust and get them to go over the car.

There are some mods to help keep an eye on the motor.If the vehicle has them then you know the last owner was trying to look after it.
The mods are a EGT and Boost guage to monitor Turbo boost and EGT temps and some people also block the EGR and install a dawes and needle valve to control the turbo boost better and make the motors run longer.

I'm sure you will get better answers than mine.

Cheers

[YNOT]

G'day Robbo, welcome to the forum.

Your best bet is probably to have a look at the reference document found here;
http://www.nissanpatrol.com.au/forum...rence+document

Most ZD30 failures can be traced back to a faulty Mass Air Flow sensor, located on the outlet of the air filter housing. Do a search on here for a thread I did called "cleaning MAF sensors". In a lot of cases, crank case ventilation oil mist fouls the sensors, causing them to send incorrect signals to the engine computer. The end result of which is usually overfueling, excessive EGT's (exhaust gas temperatures) and melted pistons.

The first modification I would recommend to any turbo diesel owner, not just ZD30, is to fit boost and pyro gauges. While they wont stop engine damage, they are your best hope of seeing when something has happend, and hopefully you notice in time before any damage is done. If you notice your EGT's are suddenly going significantly higher than normal, take your foot off the accelerator, the temperatures will drop quickly.

ZD30 turbo boost is controlled by the engine computer, although at times it doesn't seem to do a very good job of it. This is why a boost gauge is important. I've seen reports of boost spikes of over 25psi. On it's own that won't damage your engine, but it can damage your intercooler.
General information about diesels; The leaner they run, the cooler they run (the opposite to petrols). More boost, within reason, will lower your EGT's.

To prevent oil mist getting to the MAF sensor, you need to fit a catch can or PCV filter. I fitted a Mann Hummel Provent 200 filter to mine, a reasonably easy DIY job.

To better control turbo boost I have fitted a Dawes valve and needle valve set up. The Dawes valve controls the maximum boost, the needle valve controls the rate of spool up. I have my boost set to 15 psi maximum. Again this is a reasonably easy DIY job.

Another common modification on ZD30's is to block the EGR (exhaust gas recirculation). Although not legal, when you see how much carbon builds up in the intake manifold, especially when combined with the crankcase ventilation oil mist, you can understand why so many people do it.

That's the basics, there is a lot more detail in the reference document.

Tony

[Robbo]

Thanks for that, im looking at a couple today the mods.

cheers

[Robbo]

Thanks for that info, very informative. Would you do those mods on all ZD30's or just pre 2003.

Dave

[YNOT]

I would do it to all pre common rail ZD30's. I have an '03 that I've done all the mods to.

Tony

[TOECUTTER]

X2 what YNOT said. I have a 2000 GUII (AKA Grenade) and have put 196,000 K's on the clock. I love this motor and it has given me very little problems. I have done all the usual things as listed above and I maintain it very well (I am used to constant maintenance...I used to drive a Landy). If you do the mods, monitor and keep up good oil and filters you will have no probs.

This is my third Patrol (G60, GQ and the GU) and I think it is the best one out of the lot.

[mrpuncii]

Thanks man!
Is there statistics of ZD30 lifespan in Kkm or K Miles?

[BigRAWesty]

Thanks man!
Is there statistics of ZD30 lifespan in Kkm or K Miles?

No, they don't last long enough...

[y61patrol]

Very funny!!! Check your Maf,keep on top of oil changes an shell be right...apart from when she blows up!!!