Thursday, May 25, 2006

Cat Diesel Engine 3116 - removing injectors





Cat Diesel Engine - Removing an injector on a 3116 does not take long with a bit of manuevering and the right tools.
The beauty of this diesel engine is the fact that there are no fuel injection lines to fight with because of the common fuel gallery in the head that is fed by the transfer pump located in the governor housing.


  1. Remove valve cover.
  2. Remove 4 bolts holding down the rocker shaft assembly for whatever cylinder you're working on.
  3. Remove rocker shaft.
  4. Remove injector hold down bolt with 5mm hex driver Cat # 1U-8013
  5. Carefully pry underneath injector steel body{opposite side of the injector rack} with an appropriate tool Cat # 5P-0302 / a small heel bar will do.
  6. Swing injector towards the front of the engine to disengage the rack assembly.
  7. Pull up and wiggle the injector out of head.
  8. It's important to note that the injector sliding fuel rack should not be moved until the spring is slightly compressed. You'll damage the rack if you force it back and forth.
  9. If the rack can be slid back and forth easily without compressing the spring then it's time for replacement. This extra wear will cause the injector to stick.
  10. This unit I am removing did just that by sticking in the full fuel position and creating one hell of a knock, lots of black smoke and a tow bill. You don't want that raw fuel to dilute the oil in the cylinder and cause piston and cylinder damage!

That's all there is to removing an injector on a Cat 3116 Diesel Engine.

4 comments :

steve said...

I have a 3116 in a 1994 GMC Topkick I herd a small noise on the highway and now am chugging white smoke like crazy. also there appears to be raw fuel in the exhaust. Hard to find anyone here to work on it. I thought an injector failure and now stuck open. your post said that would cause a knock. Truck starts and idles good except for smoke and raw fuel from exhaust. any idea where to start Thank You Steve. highpine@sympatico.ca

John Whelan said...

steve,
I would start by removing the valve cover and inspecting the valves and injectors. A visual is the first step.

Robert Foss said...

Can the spring be replaced on one of the 3116 injectors if it is broken?

Robert Foss said...

Can the spring be replaced on one of the 3116 injectors if it is broken?