E.G.R. Disconnect.

[Miguel P.]

Originally Posted by EugeJK

One thing is for sure, its not good for the engine's internals, that’s why people go ahead blocking it. Blocking it on an old tech mechanical motor is fine, but to attempt it on a high tech electronic one is not.

The whole motor is set up to work with EGR, block it and the ECU won’t know and no fault codes arise. EGR is part of a modern engine, like it or not. It may limit the engine's life and increase servicing demands. If you must block it, look at the whole system, not just a block. Remove the EGR hardware completely, reprogram the ECU and remove the cats, then dyno the motor.

One of CJ system designers for JK in EU mentioned just this one thing, along with a few others: "The ECU closes the VGT vanes more than normal when the EGR is being used. So with the blocked EGR the vanes on the VGT are closed too much, you really need to tweak it back via the ECU so there is no change in boost due to the EGR being blocked." And so on...

I must agree with you, in theory.

But my question here is what damage this mod will, maybe, made in the engine. You said the egr is not good for the engine's internals, so no egr is good. . Apparently the problem will be the turbo and the cat (my car as no particulate filter)...but i never drive hard for long time and for me, the maximum with the jk is 140 km/h. Of course this only applies to the turbo, I think, the cat I really don't know.
I have another question for you people: "This simple mod will be worst for the motor (internals, turbo, cat, and so on) than a power change to 200hp and 500 Nm?"
One thing this mod said to me: I have a faulty egr! But how can I demonstrate this to the dealer? They said to me that the engine noise is normal...
May I have a link to the CJ system designers for JK engineer statement, please? I am very interested to read his entire opinion.
Thanks

Miguel P.

[davidd]

miguel all egr systems eventually become faulty. they always have, it's just that it happens slowly over time and you don't even notice it. the soot blowing through them eventually clogs up the egr system and without pulling off the inlet manifold, the egr valve , and the egr pipe from the exhaust mainfold to the inlet manifold, and cleaning them all out, the system cannot be repaired. it is a long and expensive job and is rarely done. this is why usually the system is just plugged off. in relation to the turbo vane position, the cj engineer is probably right. the vanes probably do stay close to teir normal position (egr connected), but you will notice the temp of the air in the inlet manifold is 20deg C cooler and therefore denser, which means that the boost may not change a lot at times. the intake air now also has a great deal more oxygen in it and can produce a better burn. these things are picked up by the engine management system as well. it is a combination of things that decides the air charge going into the cylinder, the turbo boost is just one. their is an argument that exhaust temps can rise if the egr is disconnected, and they do to some extent. however if the engine is worked hard they rise anyway and some people fit exhaust temp gauges to protect themselves as exhaust temp is not metered in this engine as far as i know. i have spoken to people in the industry ouside CJ and they say that in practice the rise in exhaust temp from blocking the egr has not been an issue with blowing turbos. in time all turbos will eventually burn the tips off the blades as the hot exhaust blows over over them for extended times, but the whole engine ages and wears as well with or without the mod. but again i can only say i posted the mod as a matter of interest to any forum members who may like to try it or be interested. am not trying to push anyone into it and say again you will void your warranty if you do it. for any of you who are happy with your vehicle as it is now and feel they want run it as is (and why not!!!) go for it. but i hope this may provide you with a quick, trouble free and cheap fix further down the track when you develop egr problems. cheers all.

[EugeJK]

Originally Posted by Miguel P.

...May I have a link to the CJ system designers for JK engineer statement, please? I am very interested to read his entire opinion.
Thanks...

This is a guy I know personally. He works for CJ in Germany. It’s not an open statement.

Everything David said above I agree with. I wanted to eliminate EGR. But I saw rougher idle and new rumbling sound, which didn’t seem right to me. With EGR on, my engine was smooth and quiet at idle. That made me thinking. There’s going to be no damage to the engine. It’s just not going to behave the way it was designed by the engineers. Not a big deal. Personally I decided to negate the mode.

[davidd]

as an aside, i was just coming home on a main road, sitting in traffic at a pretty steady 60 kph. cancelled the dash readout on fuel economy and it sat on a pretty steady 8.1 l/100 to 7.8l/100. best i ever got before was around 10.5l/100. so i'm excited. this was over a 4km distance. the roug sund you hear at idle euge is the engine timing. when you take the egr out the fuel burns better and it has the effect of giving you advanced injector timing. i got the same thing, gave it a week and it the timing seemed to correct itself. does still give a bit of rattle on a very cold morning for a while. still less than a lot of diesels. i just assumed the engine had relearnt a few things but anyway it went away. the egr gas gives a bad mix at idle and knocks the guts out of the engine power which has the effect of retrding the timing and downpowering engine so you get a real quiet idle. that's why these engines are so quiet at idle compared to other diesels. ijust worked on the theory that if it got too bad the anti-knock sensor would pick it up and do something about it, but it went away by itself so i'm happy. it runs a damned sight better than it did before. so ihave a fix (the old standard fix) for the egr fault. the other thing i have to try now is a fix for a faulty air flow valve in the throttle body. these go frequently too and cost a fortune to replace. mate of mine cut me an under size air flow valve. the theory is that if your air flow valve becomes faulty and doesn't fully open you could just put in a smaller valve that lets more air through. the air flow valve is in theory only there to help balance the egr/air intake balance. once you take out the egr valve you no longer need the airflow valve. taking it out totally gives you back the old death shudder you got from early diesels because there is no valve to shut the air off at shut down. so we're going to try smaller valves for a while to see if it is a possibility.

[davidd]

euge , is the rumbling sound you hear (assuming you have a manual) just after you have hit the clutch to change gears and the revs are dropping slightly?

[EugeJK]

Originally Posted by davidd

euge , is the rumbling sound you hear (assuming you have a manual) just after you have hit the clutch to change gears and the revs are dropping slightly?

yeah it's manual. the sound is present at idle (clutch is free) and slight acceleration. after i can't say if it's there or not coz it's not that loud. also noticed longer than before delays from crusing say @1600(60kph in 4th) to rapid acceleration. with EGR on, the delays were shorter.

[Yom]

I'm curious, is the computer in these shitboxes from VM or Chrysler?