Pretty much says it. What happens is when under neutral load (not engine braking or accelerating) for more than 30 seconds, oil seems to be building up under the valve cover and getting pushed out the vent tube and into the intake air duct. It will block out the sun when this happens, and it seems that some oil is making its way all the way through the engine (turbo downpipe has oil in it). If I run it hard and floor it up hills and otherwise work the engine, there is no problem, and its a pleasure to drive, but under light load, all hell breaks loose. The smoke is accompanied by a surge that I can control by downshifting and letting the engine burn the oil out. Quite scary.

The engine is a 4D55T with a 4D56 head, it has a rebuild that is less that 15000ks old and recently blew a head gasket (hence the new head). After putting it back together, this started happening.

I was able to observe the phenomena when idleing the engine after a cold start. For some reason, it will only puke oil on a cold start, and can idle for an hour without incident once hot.

Otherwise the engine runs very well and has good power and oil pressure.

If you have any ideas, please share them, because as of right now the truck is not safe to drive.