Very strange ZD30 symptoms

[mattyvd]

Hi all,

Just wanted to pick some brains regarding my mate's Patrol, it's a manual GU3 with a GU4 engine, has about 150,000+ km on the engine I think and mods are limited to snorkel, 3'' exhaust and apparently a DPchip. He's said it's started feeling a bit lame and starts to cough & stutter under load, with the engine light coming up. We took it for a run yesterday, I noticed a fair bit of black smoke with a couple of backfires, however after stopping or going around a corner, there's a puff of white/blue smoke initially when you get on the throttle again. It seems to get better if the car is turned off and allowed to rest for a minute or two. This has just started all of a sudden very recently. Under the bonnet, there's evidence if oil around the compressor side of the turbo, out of most of the pipe joins & around the intercooler end tanks. Don't know if it's running hot as he reckons the temp gauge is busted. Oil change has been done recently. Needless to say I've advised that he parks it up and uses the other car for a while...

My theory is that the turbo seals are going, which has basically polluted the intake tract with oil and fouled the MAF sensor, and it definately seems like under boosting/over fuelling to me, and has just started a vicious cycle of junking up. I will be changing air & fuel filters, cleaning pipes & sensors ect and clearing the ECM to make sure the basics are covered before we start diagnostics, just to avoid chasing false info. I'm a mechanical technician by trade and have experience playing with diesels, but I have a GU7 with 20,000 km and had a couple of Landcruisers before that, so not a lot of familiarity with ZD30's. In the event I can't sort it out it will be going to a diesel specialist. I'm also thinking there may be more than one problem...

Am I on the right track with this? Anything I haven't considered or should know before we start? Just trying to milk some experience/opinions/knowledge... I had my share of problems with my old 80 series 'cruiser, but nothing like this...

Cheers,
Matty

[Bigrig]

G'day mate - how about slipping over to the introductions section and throwing up a bit of information about you and your rig - a courtesy thing we request prior to asking questions etc - no harm done mate, but let's people know who they're yakking to and you'll get a better response to questions asked.

That said, welcome aboard and hope you stick around!! No doubt someone should be able to point you in the right direction with the problems you're having mate.

[WhiteGU]

Certainly sounds like a ZD30 with problems.....

All your checks are on the right track, but the very first one I would do is to eliminate a bad batch of fuel. Check for blocked CAT. The intercooler may well be leaking.

[boots]

Hi matty . you need to fit a catch can asap . a provent 200 model made by mann + hummell is a popular choice, do this then clean all your intake pipework , clean your maf . then recheck before attacking your turbo . factory intercoolers all fail and for a couple of reasons but the zd30 has a reputation for overboosting . new aftermarket intercooler and a boost guage to sort that out . thats about $1100.00 so far minimum.
plenty of research here on this forum about the zd30 . start looking and reading up . goodluck

[mattyvd]

Yea, the intercooler seals have definately bitten the dust. I hadn't considered the cat, must look into that one. I'll see if I can get a fuel sample from the bottom of the tank & pump filter/water trap, any water or crud should have settled by now. I've never seen this when I've copped bad fuel, but then again I've never owned a high km DI ZD30...

I mainly wanted to clean out the pipe work and MAF, and also check out the turbo for freeplay & leaks, then try to repeat the symptoms. I'll run ECU diagnostics before & after. If I can sort it out I'll NADS it at the same time. After that it goes to a diesel specialist...

Has anybody ever had symptoms like this? I want to consider all angles and hear all experience, no matter how wierd...

[Steve cooper]

Hi mate, this could be air in the fuel lines, possibly coming through the primer on top of the fuel filter housing or a bad hose connection somewhere. Replace the fuel hose between the filter housing and injector pump with some clear plastic hose and check for air bubbles. If air is there, swap the hose with the next one in the fuel system to find where the air is coming from ( hope that makes sense). If air is present it can also log fault codes relating to the injector pump.

Your on the right track, cleaning the Maf is a great idea, oil catch cans also are a great idea, as is blocking the EGR while u are there.

Oil around the inter cooler joins is a sure sign of a leaking end tank seal, time for a new intercooler too.

Let us know how u go dude.

Steve

[guterra]

Hey mate,

I'd be doing basically what everyone else has suggested. White/Blue smoke aint a good sign. Hopefully its just blow by being burnt up. Does he have an EGT gauge? I would hope so with 3in exhaust & a DP Chip, otherwise this may turn into a very costly exercise....

[mattyvd]

Well, this is a bit a bit overdue as I've been off the net for a while, but I sorted out the old Patrol. I thought I'd post anyway just for information, the more there is the better off we are I reckon.

The fuel filter got changed, didn't notice anything abnormal but I questioned when the last time it was replaced, so I just did it on spec anyway.

The MAF got cleaned, not a whole lot came out of it but now it's 100%.

The next thing on the list was the turbo. I pulled it off and the bearings were pretty average, so I rebuilt it, chucked it on and hey presto, plenty of boost, no smoke, lots of power and good manners. Brilliant.

I did say to my mate that now would be a good time to NADS it and fix a couple of other minor issues, but he couldn't see why it was necessary as it works fine now and didn't want to spend the money... He doesn't seem to know the meaning of the words 'routine maintenance', is pretty reluctant to pick up the tools and learn and is generally as tight as a fish's sphincter. I suggested that he either learn how to spin the spanners or learn to pay other people on a regular basis, hahaha. I did say that it's going on 10 years old now and it's normal to have a few gremlins pop up every now and then if you want to boogie off road, none of which were hard or expensive for me to fix, and that he's had a good run compared to other ZD30 owners, but he's convinced that it's a piece of shit. Hey, some people just can't be told, and it ain't my car or money. Apparently he's selling it now, and plans on buying a cheap Sierra with big tyres... Pity really, it's a weapon of a Patrol otherwise. Maybe car ownership just isn't for everyone...

Anyway, I hope this spiel helps somebody if they ever get a similar issue.

[threedogs]

Ask your Mate , fit NADS $1100 maybe or total rebuild $13,000 maybe. I'd be doing NADS, Great reply, I've tucked that one away

[mattyvd]

No dramas. Yea I said all that, but he just doesn't want to spend money. He's just hoping nothing else goes wrong, and doesn't have the inclination to do anything himself. Good thing he didn't end up buying the Land Rover he was originally looking at...

My theory is that a lack of air can behave like too much fuel. Which is technically happening I suppose, but the signal from the dirty MAF sensor mightn't have been totally kosher either. The fact is it pumped black smoke and didn't spool up a lot. Also, I think the blue smoke could have been oil leaking past the turbo seal into the exhaust housing under lower exhaust pressure, like you might have when backing off the throttle. Everything pointed to an underperforming turbo to me. I've seen this happen on turbo'd Jap cars that I used to play with after the turbo's copped a good flogging. Overboosting without a disproportionate increase in fuel delivery should theoretically cool a diesel down, up to a point that is, but jeez you'd have to pumping in some serious boost to overload the pistons... EGR flow is generally encouraged under partial loads by opening the valve and decreasing boost, and believe it or not this actually decreases EGT's. But I wonder how reliable these EGR valves are over time... After all, a ZD30 working perfectly well is a pearler of an engine... I wonder why these grenade issues never really popped up in 3.0L D22 Navara's?