Blue smoke on start up only? If on start up worn valve guides or seals around the valve guides alowing oil to run into the combustion chamber but once the engine is warm usually ok.
Blue smoke with engine running warm or cold usually a sign of worn oil control rings on pistons, instead of the oil staying where it should be it is being allowed to bypass the oil control rings and is being burnt with the air and gas mixture hence the blue smoke.
Another idea is to make sure your engine has not been over filled with oil.
White smoke usually denotes water in the mixture, this could be a head gasket blown which might also account for the blue smoke. Remove the cap on your water expansion tank and check to see if there is any oil residue or anything which looks or feels like water floating on the top.If a head gasket is blown you may find that the car is under power, what we term as missing which means that one chamber is not firing because the air& gas mixture is being lost through the gasket being blown. In most case the gasket always blows between the pots. If it is compression rings on the psitons the way to check this would be a compression check which means removing the spark plugs one at a time. remove the low tension lead from coil get someone to whip over the engine and check the compression of each cylinder if a gasket is blown one of those pots are going to be down in compression. To check if it is compression rings tip a tea spoon of oil into the bore and get someone to whip over the engine if the compression goes up you can safely say that a compression ring is causing the problem of low compression. Another reason for this can also be the Valve heads burnt or broken.
White smoke water being allowed into the chamber hence the white smoke, or even water in the oil blown head gasket.
Black smoke usually over rich engine petrol not being properly burnt.
Carlito Corway, February 2007
