ISX Cummins running crappy...I think ?

True, BUT, it could help someone else.

 

this forums was made for sharing information

 

I have a 2007 379 Pete with a Cummings ISX and a danged ole 10 speed...and I know all about not having any get up and go!!! I haul produce and at times have 44,000 lbs of weight put in my wagon...HA!
Anyway, we have 2 of the same trucks in the company, and the other truck even blows so much smoke that it looks like a freight train on the highway. We have had both trucks in to Peterbilt and Kenworth repair shops and like you say...they can't seem to find anything wrong. Once the temperature gets up on these motors, the problem seems to start, and when they are cool there is no problem. The EGR cooler and valve have both been replaced and for a short period of time, the problems were still there but the smoke went away. Then here comes that smoke again only this time was worse. (Cummings said that sometimes the EGR valves are bad even when they are new) The only solution that we found for this problem was to unplug the EGR valve...the check engine light stays on once you do this, but the motor pulls hills, stops smoking, and raises the fuel milage. This is just a temporary experiment because we still need to find out if this will cause more problems. The EGR valve has been unpluged for 1 week and so far no other problems have arised. Keep in touch and let me know if you discover anything different. Happy trucking and be safe

 

i just cant understand this about our motors. i have read about pulling these motors down to 1300 rpm's a few times. in the 06 pete i was driving(475 ISX,13 SPD.) it was out of power by 1500 rpm's and didnt like anything lower then that. so i just thought, maybe this is an older style motor and thats how it is. now i have an 09-455 hp. ISX with 13 spd. and its the same way. i pull moutain pass and baker grade almost every day. i have tryed different rpm's to down shift, but this motor does not like anything under 1550 rpm's. could it be how they program our stuff?

 

gonna try switching to the automotive setting and see if the geardown protection is on.

 

Anybody ever think to replace the fuel filter on that truck? From the first description it sounded like a cruddy fuel filter and nothing else...

 

Are you sayin, that you were cranking it to 2500 rpm and the engine went bad ? UNBELIEVABLE

 

Did anyone posting ever get a solution on the problems listed in the comments before? I've got an 05 ISX set at 475 right now, and it pulls like a freight train. I'm just reading through the posts trying to find some recent info on disconnected EGR's.

Hard to say what the problems mentioned above were, but the Cummins I have just turned 500k and won't use more than a quart of oil in 18,000 miles (longest I've gone between changes yet). It pulls strong from idle to governed (1,800 as of now), with no difference other than gaining power with rpm and boost like anything.

I'd agree with the fuel filter comment, and could even be bad injectors - it'd be worth having them cleaned and looked at.

 

I've been having the same problem for awhile now. Bought the truck a year ago and noticed it had a "turbo cough". It would let out a cough and puke out smoke. International dealer thought it might be an "air control valve" sticking. Took it to Cummins dealer and they "diagnosed" it to indeed be a sticky air control valve. They siad it wouldn't hurt it to run it that way. I put off replacing it and the problem actually seemed to resolve itself. Several months later the EGR valve decided to suddenly go out. Sudden loss of power and LOTS of black smoke. Replaced that at an International dealer ($1200.+). Ran okay for a few months, then the cough returned and engine warning light started coming on. Called Cummins and ordered the "air control valve". Installed it myself ($300.). That didn't solve anything (thank you cummins central power). Called Cummins. They said the only other thing it could be is the turbo. Replaced the turbo on 3/13 ($3200.+). Drove it 500+ miles yesterday and the problem is as bad as it ever was! Called 1-800-diesels numerous times for help. Got some suggestions, etc. from them. Contacted a cummins dealer in Hodgkins Illinois (Chicago area). They said it could be that the EGR pressure differential tubes are plugged or carboned up! I am having those replaced today..........wish me luck. By the way.... the people at Cummins Central Power in Rock Island Illinois are idiots! I think Cummins just wants to sell high priced parts by the gross. I am starting to learn that nearly every ISX Cummins will have an EGR problem sooner or later. The Techs should be well aware of this but they seem to want to keep it a secret or they're just to lazy and stupid to learn about their own products. If you're having a problem with your ISX, KEEP calling different dealers etc. You might get lucky and find one that might be able to help, rather than just wanting to sell high priced parts!

 

Those are a PITA to remove especially if they have never been removed before and the truck has some miles in it. And they're tucked down in the bottom left corner of the motor. Hope it fixes your problem!