It could be a stuck piston-ring... though this should not happen unless maybe you sucked in alot of dirt or somthing

 

hello,
You have gas in your oil, probably came from when you flooded it. If it were mine, I would change the oil again. When you flood an engine badly, the gas will sit on top of your cylinders, and will leak past your piston rings into your crankcase. If it keeps doing it take it back to dealer.

 

I would recommend an oil analysis before you do anything other than changing the oil and filter. They can be purchased from most diesel mechanic shops/ or on line.

At least with the sample you will not be guessing as to the condition of your oil.