I have a 1994 Chevy 2500 with a 6.5 diesel with a turbo. the other night it would not start. It sounded like the engine locked up. i kept trying and it finally started but it ran rough and had lousy power. Its also knocking real bad at the front of the motor. oil pressure is good. a buddy with a Cummings said that is sounds like a bad injector. he said that is leaked fuel and filled the piston up with fuel and thats why the motor locked. he loosened some nuts on top of the injectors while it was idling and on the second one on the drivers side the knocking went away. He told me to change that injector and the motor will be OK. Is that true? I hope so because I cant afford a now motor. Will a bad injector do this?

Just swap the bad injector with a cylinder next to it and use the same test to see if the knock moved. Saves the expense of buying an injector you may not need. But I hope for your sake, it is the injector.

I think you're buddy is steering you in the right direction.

so your saying a bad injector can sound just like a rod knock? how hard is it to change injectors? what do I need to do it?

Yes Bad injector sound just like knocking rods. Took me 6 weeks to learn that lesson on one of my 6.2 Diesel's years ago.

The injector is hung open, so its opening pressure is now at 0psi. No more atomizing fuel for clean combustion, you might as well be aiming a supersoaker in that cylinder.

If the injectors have 100k plus, or if the engine has had any overheating problems, you would also be well advised to change all 8.