Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
It sounds like there may be a small amount of oil that is leaking out the valve cover, (in the rear) and burning off of the exhaust manifold. You could also put some dye in the oil to have it checked with an ultra violet light, to pinpoint the leak.
With any oil leak I recommend checking the PCV system. When there is a high crankcase pressure, the oil will be pushed out. Most times it seems to get out the rear main seal. That may not be the case with yours though.
The best way to be sure is to clean off all of the existing oil, (make sure it's full) then run the engine while you look to see if it is coming from the top, (below the valve covers) or if it is in between the engine and trans., that would be the rear main seal. But you will want to check the PCV system first, to make sure that the oil is not being forced out, thanks