Why does my Diesel 5203 John Deere tractor smokes blue under load.?

while this is clearly oil being burnt in cylinders we need to ascertain what fault is allowing this to occur. worn piston rings will allow this. faulty valve guide seals. blocked breather system or turbo issue etc.

we need a garage to pinpoint root cause and give quote to fix. with luck a simple fix such as blocked breather pipe. bad luck would be worn rings ( compression check needed) etc where costs an labor involved are higher. also if massively over filled oil level it will cause excess to be drawn into cylinders too.

Hi so this is when you call in the JOHN DEERE mechanic as it has a few issues.

Blue smoke is from burning engine oil.

Fair chance the engine is shot, there is a fault in the injector pump, or engine oil is being pulled into the air intake from somewhere.