1999 ZD30 power loss/EGR

[Graal067]

Hey guys,

 

New to this but keen to learn as my 4x4/outdoor interest grows. I have a 1999 R50 3.0L ZD30DDT DOHC 16v Turbo Diesel and would like to keep it going as long as I can and do it myself. 

 

Currently its running a bit rough/turbo gauge is all over the show (will get up to 10psi and then drop to 0psi). Im thinking a boost leak? I can't find anything obvious in any of the hoses and their arn't any obvious oil leaks that I can see either. 

 

Could the EGR play a role in this? Been reading a bit and it seams like the thing to do is too block it to increase Diesel engine longivity with possibly a power/milage increase? Seams simple enough, but I'm not 100% on location and can't find any exact photos/diagrams online.

 

Like I said, new to this but keen to learn. Any help is appreciated.

 

Cheers

 

 

 

[Slartibartfast]

 

There aren't a whole lot of diesel guys on here, unfortunately. Hooking a smoke machine to the intake (if you can make or borrow one) could help track down a boost leak, if that's what it is. From my limited knowledge of diesels, I'd also want to check the wastegate in case it's sticking open or something, and maybe check the fuel filter and any water trap the fuel system might have. I'm not familiar with how EGR works on a turbodiesel but I know it'll make gas engines run like crap when the valve (or the solenoid controlling vacuum to the valve) sticks open. I've temporarily blocked off EGR for testing purposes by just bolting a sheet of something between the EGR valve and the intake manifold where the gasket should be. Might be good to start there and see if it resolves the issue or just pisses off the computer (if it has one?) before committing to pulling the whole thing apart.
 

Your best bet, if you can get ahold of one, is the factory service manual. NicoClub is a great resource for manuals, but I think most if not all of what they've got are US-spec, so that's no help for your ZD. I've got a fragment of a service manual for some kind of van that covers the mechanical side of the ZD30DD, but it's non-turbo, doesn't include much troubleshooting (just "name that rattle"), and looks like it's for some kind of van. Hopefully you can find something better than that.
 

Good luck!

[Mrelcocko]

All 3.3's or 3.5's here, but will help in anyway we can. Exactly what@Slartibartfast said. Welcome to a great family.

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[Graal067]

Thanks guys! Yeah the info online for the ZD30DDT pathfinder is pretty limited online. Heaps of stuff for the Navara or Patrol though. 

 

Ill defiantly try the fuel filter this weekend. I changed it a few weeks ago so I it could be that. 

 

Has any ZD30 owner done an EGR block?

[Graal067]

FYI changed MAF sensor and boost back to normal 

 

Worth trying to do a swirl mod with a EGR delete? Has any zd30 owner done one?

[jtchal]

Hey man, I drive a QD32 Terrano and always struggle to find information about repairs and mods. However, I managed to find something that could help us ZD30 and QD32 owners, it's a Nissan Elgrand thread! The Elgrand was produced with both of those engines and they also share a few other parts with the R50s. I'm looking at blocking off my EGR pipe at the moment hence why I've been doing all the research. I'll send you a link to those forums privately as I'm not sure if I'm allowed to post a link on here.

[Graal067]

Cheers mate. The EGR block seams pretty straight forward. I just can't find how to do a swirl mod and if its necessary. It makes sense to do so regardless and open both airflow channels but can't find any solid diagrams.

 

Also, is it necessary to add an oil catch can to an EGR block?

[KiwiTerrano]

Unfortunately the zd30 is one of the worst diesels Nissan ever made, a far cry from the earlier TD series diesels. I deliberately bought an earlier qd32 powered terrano not a zd30 for that reason.

The zd30 is known for melting piston 3 and blowing turbos. It's regarded as a matter of when, not if, it will give you major grief, usually around 170,000 kms or so. Unfortunately this is not a cheap fix and I have seen several NZ Terranos with blown zd30 diesels that have been retrofitted with a qd32 or td27 diesel.

If your boost pressure is fluctuating I'd be worried about the turbo. Could be worth taking the intake side to pieces and checking nothings loose. Does it blow any smoke?

 

Also try offroadexpress.kiwi for more info.

Edited June 27, 2019 by KiwiTerrano

[Graal067]

Yeah I have been reading a fair bit about the blown pistons. From what I know, the only issues with this one was the intercooler and fuel pump that the previous owner replaced.

 

I have changed the MAF sensor and sorted the turbo fluctuations out. I also did an EGR block and runs way better now, especially in the morning now that its winter. 

 

Its done about 300,000km so I'm a bit sceptical about doing major replacements etc since the entire engine is pretty worn and don't want to put more pressure on it with newer parts doing a better job- if that makes sense. 

 

No smoke and runs really nice now that I sorted the MAF, just looking to keep it going for as long as I can (fingers crossed no pistons go when towing the boat )

[Regan.Ingley]

Another fellow ZD30 owner here. These are GREAT engines so long as you keep a clean MAF sensor (Every service, spray it) and keep an eye on boost levels once the EGR is blanked.

Mine has 345,000 on the clock, frequently has a 2 ton trailer hooked up to it and zero issues from the engine over the last 260,000k.

 

FYI, the turbo is a VNT so boost fluctuations are from my experience, caused by the control solenoid sticking - again, a quick squirt of cleaner spray is awesome here.

My peak boost spikes to 24PSI before dropping to a steady 22PSI and EGT's don't ever seem to climb to an area of concern.

 

It's a worthwhile job to pull the inlet manifold and give it a clean, the EGR has a habit of sooting it up and results in Cyl #3 running excessively rich - This is the reason they were nicknamed the 'Hand Grenade'. Unfortunately there is no knowing that it's running like this until either, A. An inspection/clean of the intake manifold or, B. Boom!