My truck starts fine with a little white smoke occassionally on cold starts. But for the last few months I've seen blue smoke after it warms up. Each day when the engine is cold and I drive off no smoke at all. Then about 8 miles later and the engine temp is around 195F it begins to smoke. No oil in the coolant or coolant in the oil that I can tell. 230K on the engine and I use a QT of oil every 1000 miles. The o-rings on the injectors are original. Could they be the problem? But why doesn't it smoke when I first drive it when the engine is cold? Is there some other way for the oil to be getting into the engine once it warms up? Thanks for any ideas!