Hey,I'm new to the whole diesel scene,and I've got a 90 model f250 with the 7.3 idi non turbo. So the problem is itll start and run,but it has a really bad miss with a shake. It also white and blue smokes and is leaking oil from the exhaust. Like alot of oil. I don't exactly know what could be wrong with it. Just needing some advice.

 

Sounds like a blown head gasket. That'll give you the smoke, because your burning coolant and oil and your also getting oil out into the exhaust port of the head, which is why its leaking oil from the exhaust. Sound to me that the truck was way overfilled with oil. I mean ive never heard of oil coming out of the exhaust but I guess its possible if it gets past the piston rings. If youve had a blown head gasket for a while and kept driving on it .It would fry the piston rings which would possibly lead to what yoyr dealing with. But I think it would still have to be way overfilled to make it all the way out the exhaust pipe.
unless a diesel is different than a gasser in that respect.

Someone either back me up on my thoughts here or tell me to shut up bc I dont know what im talking about. Either way I'm curious to know if my thoughts are right or if not whats making it happen. Definitely a strange occurance here.

 

Like the above poster, I'm not well educated in diesels either. Might try the engine specific forum section for advice if no one else replies.

Best I've got is to remove the oil fill cap while the engine is running and see if blow-by is excessive. If you set the fill cap upside down on the oil fill, does it get blown off? Is there much crankcase pressure? That is a test I've read time and again for the old diesels.

 

here's a link on how to do a compression test.