Hi I have a 2004 1.9d non turbo, the engine was running a bit lumpy and smoking until really warmed up so I decided to change the injector nozzles and fit new timing belt kit as I didn't know when it was last done, as the engine had 150000 it would need its second one. This sorted it out or so I thought! today I started the van and it started to mis and puff smoke out again, the coolant level light was on so I topped that up and started the engine after a couple of minutes the header tank had oil pouring out of it, rang somebody who knows a bit and he said bypass the oil cooler and check if oil comes out of the pipes, well it didn't just filled the header tank up again. Could head gasket failure cause such a problem or will it be more serious like a cracked head. I don't have the gear to do a compression test, anyone else experienced this and sorted the problem?