I have a 2003 Cummins ISX in a Kenworth that has low power and smokes all the time that the throttle is off idle. It has no codes. Has a new EGR valve, I took it off anyways just to make sure it wasn't stuck part way open. It is fine. Intake system is ok(filter, tubes, etc.) Has about 800,000 miles on it. Turbo is good. Vanes open and close and is tight. Under a load, driving down road, She smokes black like a 3.0 class Cummins. In parking lot, when idling, no smoke, but when slowly reved up it starts smoking black, again like a 12v tryin to spool an HX80! It does not run bad, it runs smooth. All of the ports on the exhaust manifold are also within about 40-50* of each other when idling. Not sure where else to go with out throwing parts at it. Any help would be greatly appreciated!!

Thanks

Jay.

 

I would do an overhead and make sure all the valve lash is correct to start with

I used to run an old 400 ISX that smoked like no other, ended up being injectors

 

Alright. Will do. I was wondering about injectors, because it seems wierd that all 6 injectors are faulty at the same time because it doesnt miss, and the exhaust temps dont show it. But that would be a great place to start. I appreciate your help! I will keep updating my post as I go along.


Thanks

Jay.