Archived 6.7 Cummins piston stop hard on shutdown and hard starts

[Rogerssa]

As I fire up my 6.7 in the morning on turn over pistons sound as if there hitting kind of a knock noise. Seems to run fine and on shutdown the same knocking noise pisstons sound as if they come to a complete stop before slowing down. Can't take it to a shop as I'm in a very remote area and do not a means to get to town wondering if any one had this problem before. It's a 2016 6.7 Cummins. The sound started day before last.

 

[MichaelOverfield]

That doesn't sound good. Seems it would be internal damage.. however, it's normal for a high compression Diesel to come to a rapid stop. The alternator has a pulley to allow it to coast down slowly after the engine promptly stops for this reason. The noise you describe is what seems most concerning. Does it go away after the engine warms up? More data might help narrow down the possible causes.

 

[Dasmoeturhead]

Check all the obvious stuff 1st. I'm sure you already have, but check the engine oil level, check for oil leaks on both sides of the engine, and oil pan, check your oil PSI. Is it smoking? You say your in the back country. Did you hit anything? I mean whats happened since you noticed this? Did it start making this noise after fueling up, or putting in a fuel additive. Did you put gas in it instead of Diesel? Is it like -40 or so where your at? Did you use Starting fluid? IDK
There's a bunch of possibilities. Start your diagnosis with the easy and obvious first.

Hope you get it figured out.