ISX or ACERT, can't win?

If these #'s are even close, then I would definately go with a Cummins on a used truck with 4/500,000 on it. Seems like a no-brainer. Not to question you but are there others that would like to comment on this ???
I cannot believe someone didn't jump all over this. If its true, all the MPG discussion is secondary.

 

it may be cheaper to inframe a cummins, but you will do it more often, thus loosing the benifit of a cheaper job.

 

I don't know if I believe those numbers. Keep in mind there were numbers thrown out for Acert turbo replacement all the way from 4k to 8k. One of my drivers has an '03 Cadillac and when he needed a simple heater fan you can get parts quotes all the way from $80 to $400 just for the fan. I wouldn't purchase an engine because of internet ballpark price quotes. Also even if those numbers are correct I'd still buy the Cat, $5,000 isn't going to change my mind especially on something that will probably only happen once (if at all) during ownership. Now if it was $5k a year maybe but even then it would have to be proven.

 

I don;t know exactly why. Maybe when it went bad it derated motor. Fooling it into not working and it actually going bad in operation may produce quite different results. Some of the real wrenches on here will be able to tell you why.

 

The quote is from the same kenworth and no cats dont last between overhauls any longer than a cummins.And apples to apples most cummins will do close to 1 mile per gallon better.

 

One of the possible problems with disabling EGR in CLOSED position is that sometimes its not exactly closed. You wish and hope it is dang closed, but its not and ECM have no control on amount of fumes being introduced into cylinders, because can't move the valve into desirable position anymore.

This may cause smoking, loss of power, worse mileage, rough idle and who knows what else excessive amounts of returned exhaust will do to the engine.

Whole EGR system on ISX is probably more intelligent and sophisticated than most of its users, but it will only work well till ECM can really control it and it needs to be done precisely - EGR valve its not just open/close kinda deal. It needs to be moving nicely into every commanded position, i.e. 24% or 79% open. At least that sort of accuracy can be seen on INSITE monitoring software.

INSITE is a fantastic tool for tracing EGR related problems, especially when we can run it live, when driving. It shows these:
- commanded position (desired by ECM and/or EPA for given engine load conditions)
- actual EGR Valve position (physicly measured by EGR position sensor)
- amount of exhaust going into engine (EGR differential pressure sensor readout) - thats how I knew my second EGR was leaking, readout was thru the roof and I was smoking almost like Coga lol. Reason was EGR valve came... totally loose and under heavy acceleration would be sucked up into wiiideeee open. Then exhausst pressure would build and push it down. Interesting, ha?

Like I said, everything is nice and dandy, when the system is clean and working. But dealing with the da*n fumes, soot particles are the party crashers here. At some point in engine life (I believe idling is a big factor) EGR valve can't get exactly closed (it leaks fumes when ECM is not expecting it) and a bit later can't be even moved at all. In worse case scenario it get stuck permanently WIDE open - the we get into serious derate and limping mode and thats it.

But when it is malfunctioning we might be fooled into thinking that we had it shut by disconnecting the EGR motor signal wires (bottom plug), but its not really shut. Even ECM know that something is wrong with EGR valve position (it monitors its performance once in a while) and throw Check Engine light along with some codes - NOTHING CAN PREVENT FUMES LEAK. Thats what happened to me actually, it went broke, got shut closed (disconnected) and after 20k miles - started leaking badly. Because after 80k miles in its total lifespan this wonder broke apart internally. Its a matter of time till someone will sue Cummins for that - I believe they are doing that for profit. They f/K with EPA for money


Thats when we get to the point of replacing EGR again ($850 plus labor). Or, welding it shut forever lol

 

Seems to me, ECM is able to figure out engine power output. I have noticed, after closing the EGR (ECM knows its closed very well, its actually prevents it from working when it figures its not responding well) turbo boost went down 2psi to about 30 psi. I think absence of fumes make the engine produce more horsepower with less air.

Interestingly, when EGR valve started opening wide (although disconnected) and I was blowing hard smoke - I got like 38 psi boost all of the sudden. Which makes me wonder about real power my evil ISX can generate, because now I think, turbo boost is actually limited by ECM causing opening/closing sliding nozzle.

Anyway, ISX so-called EGR related problems are a joke compared to other internal problems you can have with truck engine. With exception of EGR cooler leaking coolant into the oil of course, but this would kill engine rather quick.

Yeah, thats a good question, HOW QUICK do you guys think? Few thousand miles?

 

Welding valve and disconnecting it from internal mechanism would allow for not having fumes and fooling ECM into thinking, it actually works, since EGR position sensor would respond proper movement. It could save us from Check Engine light and throwing codes...

Then there is diff pressure sensor...
And Im not sure if that would gain anything.
Question how ECM is actually reacting to disabled EGR is still valid, although probably there is not much difference. I still warn everyone about long, hard pulls, I can get extra 200-300 F on my pyro, and thats AFTER turbo...

Maybe there is not much sense in putting that much effort into changing internals of EGR, since engine is not compliant with emmission rules it was built for anyway, Check Engine light dont matter