Caterpillar reveals truth about EGR
Submitted: Sunday, Oct 08, 2006 at 14:10
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PatrolBen
Whilst scanning through yesterdays carsguide in the Daily Telegraph I found an article about Caterpillar dumping Exhuast Gas Recirculation (EGR) across its range of new engines. CAT belives that while it is a successful way of reducing nitrous oxide emmisions it has an unnacceptable outcome for users in the form of less performance, higher fuel economy and a reducting the longevity of the engine. One of CAT's marketing mannagers went on to say, "We made EGR work, nut we just couldn't see the value for the customer. The fuel econmy was worse, there were alot more maintenance problems so we abandoned the technology.".
CAT is now using a system called ACERT which uses a package of components to reduce the formation of nitrous oxide at the combustion point through twin turbochargers (to cram as much Oxygen in as possible) and injecting fuel in a series of shots rather than a single one and variable valve timing on the inlet valve. CAT now claims a tougher, more powerful and econmomical engine than before whilst still being as clean and green.
Now whilst we all can't go and chuck another turbo and electronic mumbo on our old engines there is atleast a solid tested argument for the plating off of our EGR systems and stop the recycling of hot sooty exhaust back through our engines. What I am interested in, has anyone managed to plate off the EGR system in a 2.8l TD Gu Patrol?
Thought I might post this as I remeber a great hue and cry about EGR a while back.
patrolben
Reply By: hl - Sunday, Oct 08, 2006 at 15:50
Sunday, Oct 08, 2006 at 15:50
Hi,
You will find that it is not such an issue in the 2.8 as there is a lot less EGR compared to the newer engines, including the ZD30. There is a procedure on the french patrol site for the 2.8 but it seems rather involved.
On the ZD30, EGR can be as much as 30% and that is more concerning. It is quite easy to do. Someone I know had his blocked off a while ago and the results are quite interesting. Performance is better in the mid range, fuel consumption is better by about 1l/100k, and to top it off, the oil stays very clean. After 1500k the oil is still very clean, similar to what you would expect in a petrol engine! So, there is certainly a lot of soot getting around the engine. Not sure what it does long term, as the engine is obviously tuned to run with it, but it does not smoke, runs better.. so... I guess it must be ok.
Cheers
AnswerID:
198292
Follow Up By: PatrolBen - Sunday, Oct 08, 2006 at 17:01
Sunday, Oct 08, 2006 at 17:01
Good to know that the 2.8l has little exhaust recycled. I had a look at the french site as you mentioned and yes it is looking rather complicated. I was hoping it was going to be similar to the ZD30 as just put a mild steel plate over the pipe with a few bolts and a gasket, refit the pipe and mr plod cant tell the difference. As the gas volume is rather small compared to the others it is looking as though it might stay (until I can find some other way ???) and I'll put up with the darned thing. I'd
hazard a guess that the better mid range performance would be due to the turbo recieving all the exhaust and hence spooling earlier and providing a tad more boost. After all nice clear cold air has gotta be better for an engine than hot exhaust.
Thanks for the reply.
FollowupID:
456927
Reply By: Member - Bradley- Sunday, Oct 08, 2006 at 23:20
Sunday, Oct 08, 2006 at 23:20
yeah at the bus conference this year there was a shmicko dennings coach with one of these new cats in it, no egr, no urea etc etc. it even used a "normal" oil like rx super !!! Cat is gonna make a killing with this new line of engines. as long as the injection system stays reliable (unlike their jackaroo system) then they will be great.
AnswerID:
198357
Reply By: Rigor - Monday, Oct 09, 2006 at 09:01
Monday, Oct 09, 2006 at 09:01
Have a 4JX1 Jackaroo and disconnected the EGR early in the piece , 98 model.
Runs smoother and gets better economy with less black exhaust smoke, also gets rid of the carbon/oil mud in the inlet manifold .The way I see it this would have to reduce the amount of soot in the oil as
well , a good diesel oil will keep this in
suspension but has to be better if the soot is not produced in the first place. The only negative that I have noticed is a very small flat spot just above idle , I believe this is because the Jack uses mnifold pressure and not airflow to meter the fuel and the EGR was contributing to the pressure . Isuzu are halfway through a recall of all 4JX1 engines (Global) to replace the injectors with a better sealing type , I am a happy chappie as after 110,000 kms I got new injectors. Blocking the EGR was easy as it is vacuum operated , just leave everything in place and insert a blockage in the tube to the diaphram .
Cheers Dave L.
AnswerID:
198373
Follow Up By: Keith - Monday, Oct 09, 2006 at 15:57
Monday, Oct 09, 2006 at 15:57
Dave
Could you give more detail on exactly which tube you blocked on your Jackaroo to disconnect EGR? If I block the EGR now do you think it will clear the build up of sludge in the inlet manifold, or is there an easy way of cleaning it out?
I also recently had new injectors fitted on recall at 150,000kms (1999 model)
Cheers
Keith
FollowupID:
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Reply By: Rigor - Tuesday, Oct 10, 2006 at 20:00
Tuesday, Oct 10, 2006 at 20:00
Hi Keith, it's the only one that goes to the diaphram on the EGR on the manifold . On my car (1998) it comes from underneath but very easy to identify. the vacuum pipe is about 100 mm long and connects to a
T junction .
It took a while to reduce the sludge in the manifold and I don't think it will ever clean out entirely unless you remove the manifold and physically clean the stuff out , I wouldn't bother doing that , as long as it doesn't get worse.
Cheers Dave L.
AnswerID:
198629