I have a 2005 T600 Kenworth with a C15 CAT. I recently rebuilt the motor but did not replace injectors or head. All seemed fine. The truck ran fine for a week after the rebuild and then it started black smoking. I put a few gallons of fuel conditioner in the tanks and changed filters. The smoke cleared up. The truck sat and idled overnight and then black smoked excessively on throttle the next day. When I say excessive I mean black soot anything and everything around the truck. When the truck got back to the yard it just black smoked/soot on the ground excessively at idle. Ive done injector cut out test all checked out fine. Truck isn’t throwing any codes. Truck cranks right up no slow start. Fuel pressure is running around 70 on gauge while going down the road. (That seems low to me) I’m at a loss as to what it could be. Turbo has been checked out and is fine. I’m not sure what else to check/try. Fuel lines aren’t stopped up. Any ideas would be greatly appreciated!!!! I have a 3406e CAT in my personal truck so not tons of experience with the Acert. I have several friends that have CATmotors and we’re all out of ideas.
When my cat started blowing black smoke it turned out to the orings on the injector tip had hardened and cracked .
If it aint smokin, somethins brokin. you are good to go Did you try cutting out each injector while its doing this black smoke? cut the injectors one at a time with someone in passenger seat to help you and see which one is causing
