we have a friend that has a 2002 dodge with a strange noise it had a injection pump installed the mechanic dropped a washer in the gears that bent the vacume pump shaft and broke a couple teeth off two gears all of witch has been replaced it sounds like there is a slight knock in the motor still the engine builder has pulled the motor apart and found no bad internals wrist pins are good thinking it might be a injector not sure any advice would be great