CAT C15 /6NZ trouble continues

Sure a few of us disagree!

 

You are joking right?

 

No joking. If the dealer can't fix it by now. Not sure if you don't think they couldn't fix it or about the problems Pittsburgh Power had on that engine they built with the blue bearings and was a disaster that they built. I'm not sayimg they are perfect but when the cat shop still can't fix it.

 

You should not have a divider valve in the lines feeding fuel to the engine. Only on the return. It bothers me that no. 3 gasket kept blowing out. Can we assume or trust that nothing happened between the time you bought the truck and received the truck? IMO you were too trusting to buy the truck and not receive it immediately. Even I wouldn't go that far. I'm not pointing blame, just saying. I will work on ecm for you today.

Call CAT at Turbotville PA. Send them by email what you have done. Years ago a top notch super well respected problem solver worked there. I THINK his name was James? Brown. At one time they had 2 people in the shop by the same name. One had a supervisor job and the other was a mechanic. You want the mechanic. I hope he still works for them or they know how to contact him.

 

How come no one has mentioned injector seats. The seats in the head on a cat can warp and cause combustion gas to leak into the fuel rail. The air then gets picked up by the injectors further down the line and causes a rough running engine and the symptom this guy is describing.
There is a guy that does injectors where I live that has a special tool for cutting the seat back true.
Detroit' Don't have this issue as there injector seats in the cup.
Cat seats in the cast iron head. The cup on a cat is only there to keep oil/coolant out of the engine and fuel.

The engine will usually act up on heavy load when cylinder pressures are at there highest.
Typically they with run fine low load like in low range . Get into the high side of trans and start gouging on the throttle the spudder and rough running will appear.

 

When this happens, doesn't middle o-ring fail and leak fuel into cylinder. Seems like it would crank a little longer, "pop" at start up and white smoke also.Thinking fuel would get a black tint from combustion gas in fuel. Swaan is totally correct, just seeing if symptoms match.

 

There is a man in the states who travels and makes this repair. He has been on here. truckenginemachinist

 

See your not understanding what i meant i dont think...it can be statically set up 1.5° +or- this is acceptable cat spec..and it will calibrate in the cat ET software. It all depends on how the backlash on the lower and upper idlers are set up on where the marks fall determining if its advanced up to 1.5°, 0°, or retarded up to 1.5°...this acceptable range is to compensate for machineing variables in the whole setup. With the new head casting the marks hardly ever end up at 0° without readjusting the whole geartrain and most of these certafied computer geeks do the least amount of this stuff and usually set it up loose and keep a little past or a little beyond the mark untill they can get it to calibrate and with the valvetrain installed this value always ends up on the retarded side of the tolerance because of the drag from the valve train on the cam...does no one get what im talking about really?

 

All depends how long its been doing it and how bad his seats are.
Generally over time the bottom O ring will get destoyed. Fuel will get into the head seat area but not necessarily get into cylinder. The seats will still seal enough to stop this. Like I said it is most apparent under higher load situations when cyl pressure is high.

 

Been going on for 18 months!