3.0L Auto Turbo Patrol - chip or not?????

Thanks DJ that is obviously another option to consider Baz

Hi Dieseljuice,

Who and where did put the Diesel/Gas on and did it really cost you only $1200?

Thanks for the help.
Giggi

Chaz,

I'm thinking of blocking the egr. When did u do it? How far did you wind back the nut on the turbo? Have u seen much difference in Fuel economy and oil colour?

My only concern with that mod is the EGR actually reduces temps in the cylinder so I figure more cold air and increased combustion because of that result in higher temps.
Then u get the other school of thought that say the induction of the exhaust at 500degress or so into the back section of the motor eg 3rd and 4th cylinders cop the most, is the reason for the melting of the said pistons?

Thoughts?
Cheers
DJ

Hi DJ,
I blocked my EGR about two years ago and have done around 30,000k’s since then. The oil stays clear or honey coloured by 10,000k’s when I change it and I’m now only using Mobil Delvac1, fully synthetic in 5W40. I did initially wind down the boost limiter by about half a turn, but that is no longer necessary because I now run a manual boost controller and control it from in the cab. My belief is that excessive boost is the main contributor to the engine failures, but a faulty EGR can help to create the problem.
EGR assists in reducing PEAK combustion temps, which have little to do with exhaust temps and you will find that after blocking the EGR valve, your EGT’s will be lower at moderate loads, but about the same at high loads or full throttle. Blocking it has also improved fuel economy and increased low RPM torque noticeably. Best of all, it has removed the annoying flat spot that so many 3.0Di Patrol owners complain about.
EGR isn’t really a bad thing, but it has no benefit in a diesel. The biggest problem for us as ZD30 owners is that it blocks the intake system when it mixes with the crankcase vent oil that you’ll find in your intake system (intercooler etc). If you remove the intake manifold on a standard ZD30, you’ll see a thick black greasy sludge that is a result of excessive EGR combined with oil. This gunk blocks the intake and restricts air flow into the cylinder, typically the rear two. The MAF reports intake air flow to the ECU, which supplies fuel accordingly, but if the rear two cylinders can’t get enough air you have a rich and over fuelling situation that ends up in excessive heat to those cylinders. Combined with higher than necessary boost levels, the result is a cracked and/or melted piston and usually a cracked cylinder head as well.
More cold air or higher boost in fact reduces EGT’s, so there is a compromise between boost and EGT’s. If you’re after longevity in your 3.0Di, then you need to lower boost, but if you go to low it will increase EGT’s. The factory ECU controlled VNT control solenoid operates to control boost in order to achieve acceptable EGR levels, but at the expense of higher EGT’s. If you have a boost and EGT gauge fitted you will see what I mean. You’ll see that when you’re climbing a hill and you put your foot down, your boost will drop away to allow for EGR. This is most annoying because it sends the EGT’s up and you loose power when you need it the most.
Blocking the EGR is only part of the solution, but a very important part and the guy’s over on the Patrol4X4 forum have been working on a solution for some time to overcome the ZD30 failures. It’s still fairly early days, but there are a few that are getting into the higher k’s without any problems.
My thoughts are to block the EGR, fit an oil catch can, run a manual boost controller and use the best quality oil you can afford. So far this has worked for me.
You can see most of my mods HERE.
All the best,
Chaz

And for all those sceptics out there that don’t believe this, just ask yourself why the ZD30 Navara doesn’t suffer the same amount of engine failures. The answer is that it uses a different EGR control system and not a VNC Turbocharger. It has nothing to do with the intercooler.