grenade engines

[jaxom28]

Some terrano's have a 3 litre engine that has a reputation as a grenade. What is it that goes bang and why?

[lax2wlg]

I believe the EGR system causes it to melt pistons etc.

Seems like almost every major manufacturer is the last 10-15 years has had a light duty diesel engine that suffered from catastrophic failure, and it can always be traced back to the emission control system.

http://www.patrol4x4.com/forum/nissan-p ... ure-28099/

[jaxom28]

Thanks for the speedy reply lax2wlg, the link was interesting reading.

[Gyxx]

Hey dude.
Never had anything to do with them myself so I'm not speaking from experience but "The Dog and Lemon Guide" has this to say about them:

" ENGINE PROBLEMS - The air flow meter on the 3.0 (ZD30) turbo diesel engine fails at high mileages, frequently causing melted pistons and therefore a total engine overhaul. "

[tweake]

Some terrano's have a 3 litre engine that has a reputation as a grenade. What is it that goes bang and why?

no one really knows for sure. nissan have never said there was any fault let alone the cause.

theres several things.
one is piston or rings issue. there is a number of piston/ring changes over the years. the later ones seam to be more reliable.
this issue is notable in that only the piston fails, head is usually ok.

MAF failure or getting dirty is an issue.
what doesn't help is nissan band aid fix was to shorten the dipstick to increase oil amount. this means the engine blows out more oil, which adds to the intake fouling and burning oil adds to egt temps. however when engine is turned off the hot oil mist drifts back up the intake line and fouls up the MAF sensor. plenty of reports of air filters coated in engine oil.

unfortunately the ecu uses the MAF to control the fuel AND the turbo. so when MAF plays up the turbo operation goes haywire and causes overboost, huge back pressure and INCREASES EGR.
to compound things intercoolers are known to crack and leak which further upsets turbo control.

failure generally cause pistons to fail and crack the head.

common fix is take the turbo control off the ecu.

then there is a few issues with the injection system, especially the VP44 style pump. timing piston tend to wear causing retarded injection timing. that further complicates the turbo control issues and egt temps.

[Crash bandicoot]

As above there is no accurate diagnosis as to why it happens but there are some very obvious things that don't help the situation.

The zd30 is a high strung engine from the get go...forced to meet stricter emissions controls but still make power that the market desires/demands it was a new design and new injection system to Nissan at the time. Any Nissan diesel before this was... what could be called conventional and with conventional came reliable.

The zd30 internals are light the zd30 having the lowest piston mass of any of Nissans engines...less mass equals faster heat saturation. That isn't a good thing if the cooling system or engine management system isn't working at 100%.

Common rail or direct injection. Nissan wasn't the only manufacturer to suffer these issues. Toyota was another. Valve seats not sealing properly allow excessive carbon from the combustion process to mix with the engine oil blocking piton rings and galleries etc..

Block design zd30 failure s always seem to involve the no4 piston. Water jacket circulation perhaps? Or that's the furtherest the oil has to travel...who knows.

[tweake]

As above there is no accurate diagnosis as to why it happens but there are some very obvious things that don't help the situation.

The zd30 is a high strung engine from the get go...forced to meet stricter emissions controls but still make power that the market desires/demands it was a new design and new injection system to Nissan at the time. Any Nissan diesel before this was... what could be called conventional and with conventional came reliable.
.........

Block design zd30 failure s always seem to involve the no4 piston. Water jacket circulation perhaps? Or that's the furtherest the oil has to travel...who knows.

i would not call it overly high strung. compared to the fat lazy 4.2 then yes. compared to the other small high out put engines of the time not so much. at the time it was regarded as quite an efficient engine.

it was one of the early "high egr" engines, especially one using hot EGR

they seamed to fail in no3 and 4 cycle the most. but typically these run hotter in a lot of engines anyway. also some say the patrol zd30 inlet manifold design looks like it feeds more egr into the two rear cylinders. normally that wouldn't pose a big problem, but if the control system is faulty and feeds excess egr in then those two cylinders will fail first.
excess egr increases inlet temps which causes EGT's to go up.

[lax2wlg]

Some terrano's have a 3 litre engine that has a reputation as a grenade. What is it that goes bang and why?

no one really knows for sure. nissan have never said there was any fault let alone the cause.

theres several things.
one is piston or rings issue. there is a number of piston/ring changes over the years. the later ones seam to be more reliable.
this issue is notable in that only the piston fails, head is usually ok.

MAF failure or getting dirty is an issue.
what doesn't help is nissan band aid fix was to shorten the dipstick to increase oil amount. this means the engine blows out more oil, which adds to the intake fouling and burning oil adds to egt temps. however when engine is turned off the hot oil mist drifts back up the intake line and fouls up the MAF sensor. plenty of reports of air filters coated in engine oil.

unfortunately the ecu uses the MAF to control the fuel AND the turbo. so when MAF plays up the turbo operation goes haywire and causes overboost, huge back pressure and INCREASES EGR.
to compound things intercoolers are known to crack and leak which further upsets turbo control.

failure generally cause pistons to fail and crack the head.

common fix is take the turbo control off the ecu.

then there is a few issues with the injection system, especially the VP44 style pump. timing piston tend to wear causing retarded injection timing. that further complicates the turbo control issues and egt temps.

Thats definitely a more useful response than mine lol!
Interesting info, my understanding is that it was regarded as an 'otherwise good engine,' saddled with problematic emissions controls.
Thats crazy about the overboosting, shit I wouldn't want to be involved when it started playing up and running away

[BlakeNZ]

those that have experienced the grenade often say " it started going really well, heaps of power, just before it melted the pistons".

[lax2wlg]

I was reading a couple of years ago that the Aussies have a preventative maintenance scheme that they playfully refer to as 'NADS.' Up until then, I thought nads was just slang for a big set of sweaty testicles.

Wait I'll look it up again....
http://www.mypatrol4x4.com/topic/57-nad ... tep-guide/

Oh yeap looks like tweake is bang on as to the causes of failure

[tweake]

i tend to follow the patrol zd30 due to the navara also using the zd30, but in lower powered version that doesn't have a lot of the issues the patrol/terrano version does.

[jaxom28]

Thank you all. Mystery phrase is explained.