3.0 DIESEL RELIABILITY

[ws49]

I found this comment on an Aussie forum concerning problems with their 3.0 litre diesel versions:

Most engine failures seemed to be caused by fouling of the Mass Air Flow (MAF) sensor with crank case ventilation vapours, causing the sensor to send incorrect air flow data to the engine computer. This results usually in over fueling, raising Exhaust Gas Temperatures (EGT's) to dangerous levels, which melts pistons and damages other engine components. Air flow into the cylinders can also be reduced (by Exhaust Gas Recirculation (EGR) carbon combining with the PCV oil vapours building up in the inlet manifold. Reducing air flow to the cylinders makes the over fueling situation worse.

I have a 2011 Patrol with a 3.0 litre diesel. Should I be worried about reliability issues? Has this fault been rectified in later engine models?

Thanks.

[Peter Connan]

The problem was eased (note, not fully rectified) by enlarging the sump around 2003.

However, it is probably a good idea to re-route the breather to an oil catch can (manufacturers cannot do this as it adds to emissions), so that these vapours cannot reach the MAF. It is also prudent to install an EGT gauge to monitor cylinder head temps, and a dawes valve to prevent overboost.

Unfortunately the damage caused by excessive cylinder temperatures is cumulative and cannot be detected. The material of the cylinder head and pistons could already be weakened by temperature spikes and protecting them from further spikes doesn't necessarily guarantee that failure may not occur later on.

[Grant]

Hi

Understanding from Nissan SA is that this was rectified in 2006. EGT monitors the exhaust gas temp, and I would suggest that you have one fitted. I have a full system fitted that also includes coolant temp, level, oil temp, pressure etc. this saved me on my last trip as my radiator sprung a leak.

Also some school of thought about the oil catch can. Two performance shops suggest not fitting the oil catch can as this prevents oil lubeing the turbo on the inside. Also a comment was that the oil collects dust and thus reduces the chance of it damaging the turbo blades. Note this is there comment and not mine

Suggest you also contact SAC diesel in centurion and talk to Mynhard or Gerhard.

[Alex Roux]

I used to have the 3td and inherited what I presume was already partially damaged pistons. I bought a 2004 model in early 2010.
In your case, I think the engine is still very new and the cumulative damage to date, is probably limited.
After the handgrenade I opted to convert to a petrol engine.

All of the above comments apply, and have been repeated on several threads on this forum.
In addition to these, if I were you, I would also be tempted to get a larger intercooler installed.
I understand from Grootseun (Driko) that the EGT shows the temp rarely if ever reaching the danger levels after this installation / coupled with the oil catch can.
If it does go above say 650 degrees, stopping next to the road and let the engine idle for a few minutes, and the EGT knocks down to around 100 degrees within a few minutes.

Some also argue that the damage done to these engines has to do with the way we drive. I.e. we tend to cruise at lower revs. Going uphil the turbo does not give the driver the sense that the engine is struggling. Higher revs and hence more ventilation is better.

[Peter Connan]

WS, I apologise.

I misread your mail, and thought you had a 2001 model!

The mods I mentioned remain valid, but I would not have belabored the cumulative effect of the damage quite as much had I read properly.

[ws49]

The latest model I can find on any Aussie forum that bombed out was a 2006. Has anyone with a later model ZD30 had related problems? It's hard to believe that Nissan, with all the technology available to them, has now not rectified this problem.

[ricster]

I must say that I haven't heard of a newer (post 2005-6) having had an engine failure, in SA, due to the "hand grenade" issue. I think and have heard that this was sorted out from the 2004 model on. BUT, ( and this is purely my opinion ) I am not that confident that this was solved successfully in the 2004 - 2006 models. Yours being a 2010 model, I would say that yes Nissan would have sorted out and made corrections to the computers etc to monitor and adjust fueling to prevent this problem from doing damage. There really is nothing wrong with the 3.0 ZD motor in the patrol. Even mine with a TD4.2 ( aftermarket turbo) has to watch the EGT's carefully when working my patrol up a long uphill.

That said, and as mentioned by basically everyone here, it would be well worth the money to go see SAC and get a Madman monitor system fitted. This gadget monitors EGT's ( most important ), water & oil temps, oil pressure/turbo boost, and a variety of other things. I can guarantee you that once you have fitted this system you will change your driving style... not for the worse but you will drive that machine to its optimum potential without the slightest chance of damage. I have heard a few guys say " wow didn't realize what was happening to the motor before fitting that system."

You will love your Patrol even more cause that niggling worry will be out of your mind !!

One other thing I'm a FIRM believer in.... I think they say in your book to service (oil change) every 10 000km or something like that.... personally I would do an oil change every 5000km.... even on a high tech modern motor. The oil gets thinner and dirty... making it bypass easier and increasing the chance of blocking the AFM... again, just my opinion

[ws49]

Thanks Cedric. I'm stressing about this and a monitor will probably ease my mind.

[ricster]

ha ha... without a doubt bud, the best money you will ever spend !! ( wish I got comm for every time I've said that....ha ha )

[Stefan]

Hi

...

Also some school of thought about the oil catch can. Two performance shops suggest not fitting the oil catch can as this prevents oil lubeing the turbo on the inside. Also a comment was that the oil collects dust and thus reduces the chance of it damaging the turbo blades. Note this is there comment and not mine

...

Maybe a comment on this after my own recent experience.

My wife was driving the Patrol and called me to say: "... there was a loud bang, and then just black smoke from the exhaust..." you can imagine the shivers running down my spine.

Anyway, with the help of (Tour de) Frans, the problem was identified as a turbo-house that popped off. Fitting it I noticed quite a bit of oil on the inlet hose (as I'm a mechanical retard, I had to loosen the clamps on all the 'top-level' hoses to properly tighten the offending clamp)

My mechanic told me about the oil close to the turbo at the previous service so I took it in for them to look at the turbo. Apparently the turbo-shaft runs on 2 bearings and the lubricating oil for those bearing is delivered onto the shaft between the bearings. Readers digest version: turbo is still 100%.

Remaining problem: There was still significant oil on the inlet side of the turbo and this could obviously cause the pipes to pop off again. Now the way I understand a turbo (please see above for my mechanical pedigree) is that the 2 sides are separate and that the inlet side is driven by exhaust gas and the other side sucks in air, so there isn't any danger of the offending oil finding its way back into the engine, but it is coming from somewhere.

When the guys removed the tappet cover, they found the PCV (Positive Crankcase ventilation) valve to be totally cover up with carbon, this they sent away to be acid cleaned.

The way I understand it, it is from the output of this PCV valve that the oil in the turbo inlet pipes came, and it is also this pipe (PCV output) to which the oil catch can gets connected.

So back to my comment on Grant's comment on the other shcools of thought:
1. On the ZD30 patrol, the lubrication happens on the shaft of the turbo, not via the oil/vapour that should be trapped by the oil catch can
2. If the oil is catching the dust, you may want to think about replacing your air-filter.