3 litre Diesel EGR valve block off

[Owen Douglas]

I have just read some very good information on contamination of the MAF sensor causing false readings to the ECU and resulting in overfueling in some cylinders and eventual piston damage. Options for correction included a "catch can" or blocking off the EGR altogether and fitting a manual "Dawes" control unit.

Reducing Exhaust Gas Temperatures appears to be the main issue for prevention of engine failure &/or increasing longetivity.

This leads to other questions such as does chipping this motor lead to higher EGT's?
I have also heard the increasing exhaust size will overrun the turbo which will eventually fail through lack of oil supply.

The "economics" of engine "add ons" for improved fuel economy/performance needs to be balanced with the cost of expensive engine replacement. I am therefore after comments on this issue and specifically if there is an "expert" in Queensland who is experienced with fitting the Dawes unit & related modifications.

[growler2058]

G'day mate welcome aboard they're a good mob here full of useful info and advice! Ynot will most likely have some answers for ya mate. While ya waiting jump over to the intro page n tell us a bit about u n ur troll We love foters here to mate so chuck em up if ya got

Haha look if I read properly it is in intros hahaha mayb try the mech section as alot of members don't read the intros:-) still if ya got foters......

[YNOT]

Welcome to the forum Owen.

"I have just read some very good information on contamination of the MAF sensor causing false readings to the ECU and resulting in overfueling in some cylinders and eventual piston damage. Options for correction included a "catch can" or blocking off the EGR altogether and fitting a manual "Dawes" control unit." If you haven't already, have a look at this thread; http://www.nissanpatrol.com.au/forum...ghlight=gren02


"Reducing Exhaust Gas Temperatures appears to be the main issue for prevention of engine failure &/or increasing longetivity." Correct

"This leads to other questions such as does chipping this motor lead to higher EGT's? " Not if the chip is properly programmed. A properly programmed chip will not rely soley on extra fuel to make extra power but will adjust other parameters such as injection timing and boost to get more power while still keeping the EGT's within safe limits. There is also an Australian made chip sold under the "Chip It" banner that includes it's own EGT sensor and reduces fuel if it see's excessive EGT's, something to consider.

"I have also heard the increasing exhaust size will overrun the turbo which will eventually fail through lack of oil supply." Fitting a bigger exhaust can cause overboost issues on these engines but it can be controlled by either fitting a Dawes/needle set up or adjusting the boost limiting grub screw on the turbo. An overboosting turbo can also damage the intercooler.

"The "economics" of engine "add ons" for improved fuel economy/performance needs to be balanced with the cost of expensive engine replacement. I am therefore after comments on this issue and specifically if there is an "expert" in Queensland who is experienced with fitting the Dawes unit & related modifications." The only workshop that I know of personally that fits an engine saver kit to ZD30's is Brisbane Turbo and Tuning Centre.
Where about's in this fine state of QLD are you?

Tony

[Owen Douglas]

Thanks Tony. I'm in Toowoomba so Brisbane is fine. Sounds like you know what you're talking about - might need to contact you again.

[Woof]

Hey Owen, just moved your post to this section as not everyone reads the introduction section, can you please post up an intro in the intro section again with just a bit of info about yourself, where you live and of course you Patrol, thanks mate

[YNOT]

Thanks Tony. I'm in Toowoomba so Brisbane is fine. Sounds like you know what you're talking about - might need to contact you again.

There's been some frosty mornings in Toowoomba lately.
Ask any questions you want, we're here to help. I have a GU3 3lt and have done the engine saver mods to it.

Tony

[Yendor]

Hi Owen, and welcome to the forum.

Yes the first thing I would do (did) is fit a catch can, this is the easiest and will not cause over boosting or any other problems.

Then I would get a boost gauge and pyrometer fitted (EGT gauge).

I had my chip (Steinbauer) and 3" exhaust fitted by Motsons, I am guessing they adjusted the boost grub screw because I never had an over boosting problem.

But yes I found with the chip fitted I could easily get very high EGT's.

After blocking the EGR and fitting Dawes my EGT's run much lower.

Cheers Rodney

[DrHarry]

Having read lots on the forums about all these topics, one question that I keep coming back to is this. In the effort to control overboost after bocking EGR and fitting a 2.5' mandrel exhaust should/can I:
1) Fit Dawes valve
2) Fit Dawes valve plus needle valve
3) Fit needle valve only
4) Adjust VNT screw
5) All of the above?

My GU is a 2008 CRD (with gas) and despite many folks thinking that these are less prone to erratic boosting mine is now regularly hitting 20. This isn't enough to put up a code but I believe it is too much? How much is too much? How worried should I be?

I gather I should be aiming for <15psi consistently?

Also my EGT is tipping 700 at times on the open road. Hopefully the drop in boost I seek will also help this?

Thanks knowledgable ones!

Harry

[Gert B Frobe]

DrHarry,

Where is your probe situated for your pyro? If it is downstream of the turbo temps should be lower but if its in the manifold they will be higher. My experience has been in marine diesels so big engines and the pyros are fitted pretty much directly after the head, but engines of this size have the room to place probes in optimum positions. The only "downfall" to placing the probe in the exhaust pipng is it will read an "average" temp across the cylinders. The manifolds on small capacity diesels can be very difficult to place sensors for accurate readings.

Just my two cents

[DrHarry]

It's in the dump pipe after the turbo I believe, as it was installed with the exhaust. Excuse my ignorance I thought that's where they all are?

I better have a closer look!