12.7 detroit smoking and rattling

I’m surprised you got it into the shop, without waiting a week or two.

 

Sounds like they're guessing. They should swap it with another injector, see if the fuel follows the swap. I'd bet quite a bit it would still be #5. I figure they'll get the same result you did after replacing all 6.

I hope they're right. Wiring issues, fuel return blockage, and timing issues are pretty well dismissed.

The only things left are injector and valve, piston issues.

I have little faith in even the big shops. One of the local counties called me about three years ago with a similiar issue on a Cummins. Freightliner a 1/4 mile from ny shop had this truck three months.

Replaced injectors, injector harness, turbo, and EGR valve. Still not fixed, they used the excuse that it had been deleted to say they couldn't work on it, and charged them 17k.

They brought it to the shop. Cylinder c/o showed the suspect cylinder. Pulled valve cover and rolled the cyl tdc. No interference from rockers (no jakes). Pulled rockers and found 1 exhaust valve 1/4"" lower than all others.

Seriously took less than an hour to diagnose

 

Very common on cat to have to go through multiple injectors to find 6 good ones .. I’d suspect Detroit is probably getting to that stage as well .. nowadays many guys won’t change injectors on a inframe unless they know old ones are bad .. new ones are a crapshoot

 

Dod you replace them yourself, or do you have a mechanic capable of that?