Isuzu Trooper Owners Club UK™

[Wookie]

Hi I was wondering if any on here have disabled the EGR valve on the Rodeo Denver Max 2.5L 2006 model.

   Or does the ECU make this a no go?
   
    Would it also damage the Turbo, to do this?
 
   Where exactly is it?  I had a quick look yesterday

    Col

[Google]

[freebiestuff]

See my reply here http://www.itocuk.co.uk/forums/viewtopic.php?t=13500&start=30 The EGR valve is on the top of the engine at the rear on the right.  There's a pipe coming from the exhaust manifold to the inlet, with a big silver canister in the middle.  The valve is the bit on the inlet end with a small rubber vacuum hose attached, it should be held on with 2 nuts and 2 bolts.

Col

[Wookie]

Thanks, that makes it clearer where the valve is.My engine looks similar to the one in that post,with the big heat exchanger at the back.Though that engine appears to be an old 2.8L fitted with all the 3.0L Denver addons.Which is as far as I am aware is what the new ( or 2003-2004 rodeo ) engines are basically,rebored 2.8s , up or down to a 3.0L or 2.5L.    I  think.    

 Its still unclear to me however,whether it works safely.I've read on other forums that you can damage your turbo with the increased temperatures?I still don't know if the ECU causes problems?

 From the posts I've read on here it seems its still unclear as to whether it works ok.Would I be right in thinking that ChrisB has done this?He says he has,but i'm unsure if its in his Rodeo Denver Max LE or an older model?

  Maybe its still an ongoing experiment.

  Col

[Wookie]

Nobody know the answer to this?

 Well i tried to remove the vacuum pipe yesterday,but the way its connected is through a small hole in the valve housing and i cant really see the end of it.I tried pulling it of when hot or cold but it seems like I will only stretch it to breaking point this way,as it well stuck on.The only way to do this properly is by undoing the bolts and taking things apart.
  I thought maybe I could try clamping the pipe together with something and see if that makes any difference.

  Col

[Lostheplot]

I know this topic is a bit dated now but I am also interested in disconnecting the EGR.
These are primarily fitted to burn off NOx etc that wasn't burnt first time around by repassing it into the cylinders. It also puts in a load of polluting combustion products that turns your oil to cr*p and displaces oxygen from the intake air. Also it fights the intercooler, which is there to reduce intake air temperature in the first place!
My motor is a 2004 2.5tdi with a vacuum operated EGR, so disconnecting is easy, no blanking required, as in the early mechanical L Rover system, just pull off and blank the vac pipe and the EGR will stay closed.
I looked at the heat exchanger between the exhaust manifold and EGR and realised it was there for two purposes, both of which could be disregarded; one to speed up engine/cab heater warm up in VERY cold climates and two; to cool down the recirculated exhaust before it entered the inlet manifold. Exhaust temp is about 200C ish and coolant water is about 90C ish.
So, I will be disconnecting this week and keeping track of fuel consumption, which should improve due to the lower charge air temperatures.
I am currently doing 37mpg on a regular run between N W Wales and the Midlands, a mixture of winding hilly A roads and the M54/M6. Driving at the legal limit on the motorway and 60mph on the A roads.
I should add that my Rodeo is a 2WD whicm may help fuel consumption, but I have also had it chipped up to 130HP, which improved its driveability fantastically.
Los

[eithan h]

it is also there to reduce combustion temps so you don't melt the tops off your pistons

[Lostheplot]

it is also there to reduce combustion temps so you don't melt the tops off your pistons

Mmm but if I remember correctly the 2.8td MK1 trooper did not have EGR, and since the 2004 2.5 and for that matter 3.0 engines, are basically the 2.8 re-bored, I suspect that the engine will cope with the increase in combustion temps because it was designed for non EGR temps anyway. My 2.5 always takes an age to warm up and runs a reasonably cool water temp (thermostat is OK) so, I'm betting that it isn't a problem. Even though combustion temps are localised heat with a high deltaT to the engine structure (and the pistons are not well cooled), significant increase in combustion temp should be seen in the coolant warm up time, (before the thermostat opens).
The only difference may be in compression ratios. If an engine has a bolt on addition of EGR, like I suspect the 2.5tdi in my Rodeo has, then Isuzu may have been tempted to increase the compression ratio from the original 2.8td, to take advantage of the lower gas temps. Does anyone know the compression ratios of the original 2.8td versus the 2004 2.5tdi?  
Also because my engine is chipped, it is increasing the fuel injection time, more fuel = more heat, so I may have to watch that.
Higher than designed combustion temps will cause localised hot spots on the pistons, which will cause pre-ignition of the fuel and knocking under acceleration, so there should be some warning if combustion temps are approaching dangerous levels.
Many people using 2.5td Mazda engined vehicles disconnect the EGR and I have not heard any adverse reports yet and this is a very similar engine to the Isuzu.
Los

[freebiestuff]

Any debate about EGR usually ends up going round in circles, my tuppence worth.  Yes we use an intercooler to cool the air, but in order to increase volumetric efficiency, not cooler combustion temps (it actually leads to higher combustion temps.)  EGR valves do not reburn exhaust gases to get rid of more NOx, they displace oxygen in the air charge thus reducing the combustion temperature which in turn produces less NOx (NOx production being dependant on high temperatures.)  Removal of the EGR system won't make a huge difference to driveability or fuel economy as you still have a particulate filter downstream, restricting the gas flow, remove it and you might see a bigger difference.

Col

[edwin]

Hi all,

I blanked the EGR valve of the 2,5TD rodeo 2005.
Only have problems with the check engine light on long higway routes with the same rpm.
On normal smal road driving with variabel intake valve stands no problem at all.
Power gain or better mpg not really  

[Chris B]

The threads posted by me regarding EGR blanking will be from my 3.0 Troopers... so far this motor hasnt been touched as its under warranty.
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Isuzu Rodeo Denver Max LE | 265/65R18 BF Goodrich AT               LTM No.60

[edwin]

[eithan h]

ok but taken from the manual where isuzu probably spent millions looking in to this and you have spent how much?

[edwin]

and you have spent how much?

5 years school as car mechanic
2 years school as a car expert
10 years running a shop with carparts for the aftermarked.
and the last 5 years leading the main garages and busses of the public transport in Belgium, and working verry close with Eminox ltd for the nox and small particel soot control on the diesel engines.

I can tell u one thing,the only purpose of EGR is the cheapest way for the motor constructor for getting the 'euro 3' emission norm with an old engin.
The millions on research are spent on the common rails and further on for getting the new 'euro 6' in 2012 (noticed the car prices?)

Selling is here the main intrest not the lifetime of the engin, or power otherwise rudolf diesel had put one on the basic concept of the engin , a diesel needs oxygen/diesel mixture and pressure for detonation,not exaust gas the remaining oxygen an diesel is just to low.

Lower combusion temp?, yes exhaust gasses just won't do the job, not in creating much horspower and also not in temp witch is a lost counter product for creation of the horsies.

Sorry eithan h you c'ant convince me, but probably you can improve my English writing alot  :wink:so feel free to correct me.

[eithan h]

when the egr was invented there was no euro 6 engines and isuzu spent millions along with other manufacturers in making the emissions lower and this was what they came up with, common rails had probably not even been thought of back then.

it was also introduced to lower the chances of detonation or pinking or predet what ever you want to call it not the detonation of the mixture itself.

as yourself has proved there was no real gain in mpg or power but you feel that despite gaining nothing you want to risk everything even melting the top off a piston due to combustion temps maybe going higher than the engine was designed to cope with and introducing predet as well.

good luck but personally gaining nothing and maybe ruining the engine is to big a chance for me to take on a vehicle, you obviously have deeper pockets than i do!!

[richard wilkinson]

this getting good
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isuzu 3.0 about to be a 3.1 it is now
vauxhall astra club 1.6