Caring for your diesel

Hi just wanted to put out there that 4WD action had a really interesting article on caring or protecting your diesel engines, mainly directed at the 3L's. They discussed how over throttling can cause over heating in your exhaust and turbo without getting you anywhere quick. They suggested getting an EGT and boost gauge to monitor what's happening inside to help notice temp spikes sooner and more efficiently then just using your normal temp gauge which in a lot of cases can be a bit late once the temp has started to climb, especially in the 2.8L and the 3L which are vulnerable to temp spikes. I have a 2.8L so it really appealed to me as I am in the process of rebuilding the engine as the head cracked, so I decided to replace all internal parts (pistons,rings,bearings,etc) and do the job properly. Obviously they went into lot more detail and and had a few other segestions on how to protect your engines but the EGT and boost gauges were their top two suggestions.

One of the major causes of early build ZD30 engine failures was PCV (positive crankcase ventilation) oil vapours travelling back up the inlet ducting after engine shut down. This oil mist eventually coats the MAF (Mass Air Flow) sensor causing it to send false readings to the engine computer. It is these false readings from the MAF sensor that often results in the engine over fueling and melting pistons. This is what people refer to as "grenading"
If you have a exhaust gas temperature (EGT or pyro) sensor you will see the temperature rise well above the 550 degrees C (post turbo) recommended maximum, the reason why pyro gauges are so important.

Regular cleaning of the MAF sensor will slow this process down but the best fix is to combine the pyro gauge and MAF sensor cleaning with a catch can or PCV filter. These filter out and collect the oil mist and stop it from coating the sensor.

Blocking the EGR (Exhaust Gas Recirculation) also helps, although it is illegal as you are tampering with an emmissions control device.
The carbon from the recirculated exhaust gases can build up in the inlet system over time and restrict air flow, again resulting in over fueling.

ZD30's have computer controlled turbo boost but at times it does not do a very good job of controlling the boost. At times it pulls the boost right down to allow the EGR to work (pointless if you have blocked the EGR) and at other times can allow boost spikes well past 20 Psi. Although the boost spikes themselves will not hurt the engine they can damage the intercoolers. The end tanks on the standard intercoolers are crimped on and repeated over boosting can loosen the crimping allowing boost to leak out. You will usually see an oil stain (condensed PCV oil mist) around the ends of the intercooler if they are leaking.
Fitting a Dawes and needle valve set up takes boost control away from the computer and lets you set the maximum boost and spool up rate.


The 2.8 (RD28) engines do not have a reputation or history of grenading like the ZD30 but the same principles apply, fit the boost and pyro gauges to keep an eye on what's happening in the engine, fit a PCV filter/catch can to keep oil mist from coating the MAF sensor, block the EGR. All of this combined will ensure the engine gets the maximum amount of air and keep the EGT's as low as possible.

Tony

Thanks heaps for all that info that really helps me.

Wow. This is a great thread and great info from both you guys. Mine is due for a service, and im gonna change the oil and fluids, but after reading this... Definitely changing the air filter and cleaning the MAF and fuel sensor.
Do you guys know how much auto electricians will charge for fitting the gauges?

Sparky's charge by the hour so it will depend how quick they are. Keep in mind fitting a boost gauge to a ZD30 requires a fitting to be welded/brazed into one of the intercooler pipes and the pyro gauge needs the thermocouple (sensor) fitted into the exhaust, both of these jobs take a bit longer to do so it's not just a straight mount the gauges and wire them up job.

Tony

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Originally Posted by teleman

Wow. This is a great thread and great info from both you guys. Mine is due for a service, and im gonna change the oil and fluids, but after reading this... Definitely changing the air filter and cleaning the MAF and fuel sensor.
Do you guys know how much auto electricians will charge for fitting the gauges?

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Do it yourself mate. I did and consider myself a novice. If you can't weld just get that bit done by a mate who can.

Quote:

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Originally Posted by brooks

Hi just wanted to put out there that 4WD action had a really interesting article on caring or protecting your diesel engines, mainly directed at the 3L's. They discussed how over throttling can cause over heating in your exhaust and turbo without getting you anywhere quick. They suggested getting an EGT and boost gauge to monitor what's happening inside to help notice temp spikes sooner and more efficiently then just using your normal temp gauge which in a lot of cases can be a bit late once the temp has started to climb, especially in the 2.8L and the 3L which are vulnerable to temp spikes. I have a 2.8L so it really appealed to me as I am in the process of rebuilding the engine as the head cracked, so I decided to replace all internal parts (pistons,rings,bearings,etc) and do the job properly. Obviously they went into lot more detail and and had a few other segestions on how to protect your engines but the EGT and boost gauges were their top two suggestions.

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Any idea mate of what magazine number this was in? i might of missed the artice :(

It was only a few issues back but from memory the article lacked detail.

Tony

Hey 1st post here,

I've just bought a Patrol with a ZD30. It has the Dawes needle valve, and blocked EGT with a oil catch can with an upgraded intercooler.

The boost is set at 13~14psi, but can sometimes spike at near 20psi.... my question is, how high can I set the maximum boost, with it still being at a safe level?

Cheers,

James

I would say twenty is too much. I had all that and more done to my ZD30 03 minus intercooler. I had mine set for 16 tops which is where you will find you over boost protection. Used to set it off O/B/P in the cold of morning before engine had got to temp. The boost does not need to go any higher than 14-16 ever. You will find with the needle valve controlling spool your engine will have good boost instantly unlike when the computer was managing it. I found that pre Dawes/Needle boost was not there when needed (5-8psi) and coming on strong when I was backing off (13-15psi or higher). Don't go stupid. These lil donks are know for issues related to boost. We do these mods to stabilise and smooth out the boost curv making the car more reliable. Crank it up and you will likely end up with a big old repair bill. My opinion. Good li engine when treated right. ZD30 Reference Doc.... Your new best friend.

Great advice.

Clean air, fuel and oil, thats the key I say. For me, I'm fitting:

1. snorkel
2. responsive engineering water watch (doesnt provide a fuel retriction so is compatible with common rail setups)
3. catch can
4. egr blocking

And doing 5000klm engine oil changes

So I'm a complete n00b when it comes to the mechanics of cars (for the sake of this topic, pretend I'm a woman haha - sorry to be sexist :P)... Can I go to the mechanic and ask them to do this and they will know what I'm talking about?

Also, is this what everyone refers to when they do the NADS?

If the mechanics half decent then yes I reckon they will know maybe try a diesel mechanic
Nads are mods performed to stop the z30 from going BOOM


Tappin N Crappin

Some great info! I've got the oil catch can, gauges and pod should be here late this week, install next week. Hopefully it will help my zd30

Is this really an issue for the 2.8? Mine is a 98 GU just coming up to 280,000k's, but i have looked after it for the last 4 years and 100K. Do i need to do anything other than regular maintenance, or is it just the ZD30's?

This is a great treat !!! i hope i will find al that f*****g sensors to clean them !

Edit: just be careful with the language mate google watches for harsh language as we're classified family friendly cheers

im confused????
does the nads only apply to turbos??
i got RB30 carby engine with duel fuel, does this apply to me??

No mate nads applies to the 3.0l turbo diesel models.

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Originally Posted by nissannewby

No mate nads applies to the 3.0l turbo diesel models.

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Might sound silly but I got no clue about all this talk about NADS, please do tell.

Im no expert on it so hopefully some of the 3l blokes will be around to tell. I think the nads is maybe a nissan anti-theft deterrent system or something. So it may also apply to some of the later TD42Ti models as well.

Nads Nissan anti detonation system you do the nads to stop the early zd30 motors from going bang due to oil mist on sensors high egts and over boosting issues so does not apply to any other motor I believe

Cheers guys and believe its early models only correct.

Yeah all the direct injection ZD30's

Quote:

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Originally Posted by nissannewby

Yeah all the direct injection ZD30's

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Ahhh yes like my mates

Hi friends i just want to ask you that i have a Diesel cruiser car but this is very expensive and using very high quantity of diesel i want to make it less
use of diesel and also protect this diesel in my car any body have any idea for this....??

Hi, just got my 2002 Y61. Im already looking at putting the EGT/boost gauges. Thanks to this thread. Aside from these, what are the other immediate services that I should to preserve the condition of my engine?

Mike

Search for NADS on here and it'll give the full rum down of meassures you can take

good read..