If the smoke smells like anti-freeze, kind of sweet smell, it is a leak in the cooling sytem somewhere. It does nto take mush of a leak to cause problems. The leak does nto have to be in the head gasket, it could be a crack in the head or water jacket around the cylinders.
If the exhaust smells like burnt oil, it is a leak in the oil system. Again it does not take much to cause a problem. The valve stem seals could be bad, the head gasket, oil could be getting by the piston rings, there are a few areas where oil can lip into cylinder, but those are most likely ones.
It might be small enough that you don't see a great loss of oil or milky stuff in oil. You might not see the drop in anti-freeze level or have overheating problem.
Sooner or later it will probably get worse.
You can test the cooling system by getting a cooling sytem pressure test. It will detrmine if the system is capable of holding specified pressure and for a certain amount of time.
As far as the oil goes, eventually it will start to burn it up quickly. The ways that oil slips into the combustion chanber are by rings or seals and they are wear items.
I hope this information helps.
Friday, October 28th, 2011 AT 9:45 PM