New member - 2004 Nav Zd30 needs engine work

[MickR]

Hi all,
New to the forum, and have just purchased a solid, but grumpy 2004 D22 with the ZD30DDT engine for work on our block. It’s done 388k and is drivable, it was sold to me with a known over heating problem. It came with a spare reconditioned head, head bolts, gasket kit. It’s drivable, the temp goes up under load, I.e. driving up hill, any speed above 100, and will drop really fast if you can let it coast. I’ve done some reading here and I’d be thinking it’s cracked the head, but it’s seems like I should also spend time in the cooling system as well. Any Thoughts here gladly taken, as I don’t want to over work

When I drove it I’m also pretty sure either one / all turbo gaskets may be gone,, or the turbo itself, as it makes a very noticeable sucking sound if you accelerate with any effort, or maintain speeds above 80km.

I’m really good with petrol engines and have no issues stripping and rebuilding these, but am a complete diesel novice. I don’t have every tool under the sun, but have a pretty well equipped garage.

So, what I’m after, is a few things initially,
1. a manual to walk me through the Head removal and replacement process, as I have not been able to find one on the net. Also, I’m thinking, new glow plugs, and upper timing chain, while it’s apart, and potential a new inter cooler. Is there something else I really should swap out, that I haven’t mentioned? How can I clean the injectors, would un ultra sonic bath work?
2. Turbo information, is there an easy way I can identify if it’s gasket or turbo? And if turbo, what brand turbo should I refer, as prices seem to range greatly, as would the quality I’m assuming.

 

[Horatius]

Here is a link to the relevant part of the manual. The head details start at page 133.

 

[Horatius]

These motors are generally very reliable (unlike the ones in the Patrol), the heads don't crack for no reason. It's likely been way overheated so there will almost certainly be cooling system issues. Radiator restriction being the most common (from lack of proper servicing). It might be worth replacing the radiator and flushing the system first, see how it goes, as a radiator would be worthwhile anyway with a new head (probably all hoses too). Little diesel motors like this don't like overheating, by the time the gauge goes right up the head is often already gone.

I haven't changed a head on one of these. Have done a couple on other brands though and didn't find it much more difficult than petrol motors. As to injectors, I'm rough enough that I simply throw the old injectors back in "as is" if they were running ok previously lol (if it ain't broke, don't fix it). I know people will laugh at that (some will be horrified). As to cleaning them, others might know. Timing gear and glow plugs sound a good idea though.

A "sucking" noise doesn't sound like the turbo itself (though I haven't heard it so cant really know). Are the turbo inlet hose and clamps ok? There are aftermarket turbos around that seem reasonable, and much cheaper than genuine hitachi. There will surely be people along have have done some recent research.

edited to add...these models didn't have an intercooler. If it has one, it's an aftermarket one afaik.

 

[MickR]

Thanks Horatius, really appreciate the advice, and the link I have down loaded that. I’ll get hold of a new Radiator and hoses and a good flush and see what that does, as you say no matter what that never wasted on a motor with km. I’ll have a good look at the turbo hoses and gaskets and see what I can find.

 

[Erick]

Ok. Take cap off radiator when cold and engine at slow idle. Look for air bubbles being pushed out of coolant. That’s a cracked head. Under load and revs it will push the water out of the radiator. If it just overheats under load, but does not lose water, most likely radiator, maybe water pump but they mainly leak before failing. My 2005 has had a cracked head since I bought it at an auction 30k kms ago. Keep the boost under 10 and speed to 90 and it’s drivable. I guess I’ll have to fix it one day

 

[MickR]

Thanks Eric, love the simplicity of the check. I’m not going to be where the car is for a few weeks(work), but when I get back, I’ll run that check immediately.

 

[Boogieboots]

I just hit 380thou on mine, no problems.
Until today. On the way home saw a bunch of smoke from under the bonnet and she started chugging pulled straight over and stopped. Popped the bonnet and found the top radiator hose had blown off, or so I thought. The end of the top rad port had snapped off! I had swapped batteries and assume I impacted and damaged it putting the new one in. I sincerely hope that I haven't damaged the engine but it seems ok with water in it again
But the thing is for the last couple of hundred thousand kms I have been wanting to change the radiator because I hate the idea of a plastic top tank and it has fkn bitten me now!

Get a new radiator anyway and not a cheap arse plastic one!

 

[MickR]

Thanks Boogieboots, yeah new radiator is going on, i have gone back and forth in my mind on this one, but it just makes sense, new radiator, and replace thermostat, full flush including heater core, new hoses if needed. Even if it makes no difference to my initial problem above, when i solve my problem i'll have a virtually new cooling system.

 

[freddo]

I just hit 380thou on mine, no problems.
Until today. On the way home saw a bunch of smoke from under the bonnet and she started chugging pulled straight over and stopped. Popped the bonnet and found the top radiator hose had blown off, or so I thought. The end of the top rad port had snapped off! I had swapped batteries and assume I impacted and damaged it putting the new one in. I sincerely hope that I haven't damaged the engine but it seems ok with water in it again
But the thing is for the last couple of hundred thousand kms I have been wanting to change the radiator because I hate the idea of a plastic top tank and it has fkn bitten me now!

Get a new radiator anyway and not a cheap arse plastic one!

T
op rad hose is far better than losing the bottom one which is major problems for any vehicle!

 

[Boogieboots]

That is good news. I have no water in my oil and no bubbles in my coolant so I am hopeful that I am in good shape.
I have another rad with plastic tanks though, needed to get her back on the road asap

 

[MickR]

Ok team, so I’m back with the car, about to get on the Spirit of Tas to bring her back to Melbourne for some kind attention. I have a top radiator hose that is super hot and pressurised and a cold bottom hose, it’s either empty, or it’s not flowing. Normally I’d go straight to thermostat in a petrol engine. Is my thinking right in a diesel?

 

[Erick]

Thermostats do the same job in any motor. This time when u check, engine should be hot-running temperature but not boiling- remove radiator cap and look for flow of coolant past the cap. If u have flow all is well. If no flow ur engine will reach operating temp and beyond very quickly. A few kms.

 

[Old.Tony]

Another consideration for the temperature rising you've noticed - the cooling fan may have a viscous hub which isn't performing well. I had the exact same problems when my viscous hub needed to be replaced - gentle level-ish driving and no real dramas, work it a little and the temperature rose faster than expected, and dropped nicely when coasting.

Another possibility (because it's the same thing) is a bunch of blocked cores in the radiator. Reduced flow through the radiator caused a reduction in the ability to extract heat (which is what zero fan drive does).

Test the fan: with the engine at normal running temp, open the bonnet and while you are watching the fan, have someone turn off the engine. The fan should stop WITH the engine and trying to turn the fan should not work well, the fan should resist turning. If it rolls on for a bit after the engine has stopped, the hub has failed and that's most likely the cause of your trouble.

Repair the hub: I fixed my last one by going to a Toyota dealer and for $18 I bought a bottle of silicone oil. I opened up the hub, poured the whole bottle in and closed it - bingo. Fan worked properly.

If you suspect the radiator may be blocked, there's an easy test: grab an infra-red thermometer gun and aim it around the radiator. It should be hot at the top, and cooler at the bottom. There should not be any areas that are dramatically different in temperature.

 

[MickR]

Hi Team, firstly a great big thanks to all who responded, you have made my Navara ZD30 journey a good one so far.

We had - no thermostat fitted, so thats been replaced, we had a water pump that was literally in three pieces when i removed it, been replaced, new radiator, old one was leaking, new glow plugs, just cos i had the rocker cover off, done the ERG block, inspected the turbo and the timing chain. She is back together and running bloody beaut, lots more power and no cooling issues at all.

Oh and the sucking noise - split nissan turbo rubber air inlet pipe, taped up at present, waiting for the replacement silicon one to arrive.

One question - how does anyone fit the 11 + litres of coolant into these things, best i can get is 9. Any tricks im missing? And yep still runs super cool with 9.

 

[Old.Tony]

One question - how does anyone fit the 11 + litres of coolant into these things, best i can get is 9. Any tricks im missing? And yep still runs super cool with 9.

It's quite different to how you can fit the 5th and 6th schooner of VB in, trust me. Your Nav can't get through the door of the men's room anyway.

11 litres would be for a completely empty engine, empty OEM standard radiator, empty turbocharger, empty heater matrix inside the cabin, empty hoses (ALL of them, including any running to the firewall, EGR coolers etc) as well as an empty overflow bottle.