Cat 3406 E Engine Problems

New guy here. Hope someone can help. I have a 3406 E in my truck. It recently had an in frame overhaul. It intermittently will blow white smoke out of the stack and at the same time fumes out of the crankcase breather. The fumes from the breather smell like burnt oil and get in the cab. It happens when going slow like backing up or taking off from a stop light. After fighting it for about 1,000 hours, I took it back to the mechanic and he replaced all of the injectors. He said 4 were bad from the factory. However, I still have the same problem.

Obviously there may still be some bad parts or a mistake when putting the engine back together. Any ideas of where to start looking?

 

Thanks for the info. That's the kind of stuff I am looking for, so I can compile a list of questions/suggestions when I take the truck back.