Hello everyone, I am working on a 938h LKM with a C7.1 c/r. It's having a Diesel knock on cylinder number 3, replaced injector with a serviced one and the problem persists. The fuel volume is lower than the other 5 and there's smoke and just a little misfire. I am yet to test harness, it's brittle. machine just over 21000hrs. What am I missing, anyone experienced such in these common rails?
You say the fuel volume is lower, do you mean when performing a cylinder cut out test? That’s an indication that cylinder 5 isn’t contributing much to the power output of the engine, or at least considerably less. I would get the compression adapter for the glow plug and see what compression numbers you’re seeing.
Maybe engine knock rather then diesel knock.
Knock goes away when injector cut out
Will carry out a compression test on it
Maybe swap injector to another cylinder and see if problem moves. Has it lost its trim file? Bad earth braid on ecu can cause all sorts of issues.