Hard knock at start

More than likely fuel knock. It cleared up after some heat was made, right? Start an old b- model cat or Nc Cummins. Listen to that knocking and banging until they make some heat!

 

Same issue same engine. after my rods n mains new oil pump it's not as bad but still there so I'm assume it's normal

 

Just a cold Cummins. Like super hauler says, the old Cats and Cummins would shake, rattle and make you think they were coming out of the frame on a cold start. You would swear a rod was coming thru the block any second. And smoke the whole hillside up !!

 

Fuel leak somewhere? Feels like it's sucking air at start.

 

Could need the valves adjusted, while up there check out the rockers, inspect the cams... Could have a rocker loose or broke off in there

Just an idea...

 

Could be starter issue if it knocks, batteries and cold don't do well on it making it work harder.
Try plugging in engine block when really cold and then start, will tell you it's from the cold

 

You guys over think this crap too much. It is a cold engine with what could be a bad grid heater. It is normal for a diesel to act like it is falling apart when it is cold and first started up. The knock is more or less the fuel not burning because the metal takes the heat away from the air being cold

Below is what used to be with old cold diesels, brings back a lot of memories,