white smoke is almost always oil, that is from the excess oil that could be anywhere on the engine burning off. Check under the hood and look for leaks under the car. If it's overheating it sounds like either you ahvea coolant leak, or there isn't enough coolant flowing through the engine itself. Again look for leaks or puddles under the truck itself. If it's literally "drinking" coolant that means there has to be a leak somewhere in the system and that also means that you are losing alot of $$ for coolant. Be cautious though, because if coolant is not flowing properly or is leaking and you overfill it it will come back into the motor itself. pop the hood while the engine is cool, and look at the tubes from and to the engine coolant reservoir. Also check the cap at the bottom of the radiator, there will always be a cap for coolant to drain down there. If it's on loose or not at all there's your problem.
