Q: I have a Lincoln Mkx 07, I have no leaks but the back of my engine seems to be smoking... what can it be?

I would recommend double-checking the fact that there are no leaks. Normally when smoke comes from the engine bay it is due to some sort of fluid leaking onto the exhaust while it is hot. Many times since the engine is transversely mounted in the vehicle, the rear valve cover leaking may not be very noticeable. The exhaust manifold for the rear cylinder head is located directly below the rear valve cover and therefore will cause smoke if oil leaks onto it.