An oil-thirsty engine and smoke coming from car 's tailpipe are signs of trouble . AOL Autos : How often should you change your oil . Bad valve seals or worn guides , clogged PCV valve , worn piston rings among causes . White smoke : Water condensation from blown head gasket , too much gas . Comment: Engine oil is being burned in the combustion chamber .
An oil-thirsty engine and smoke coming from car 's tailpipe are signs of trouble . Bad valve seals or worn guides , clogged PCV valve , worn piston rings among causes . White smoke : Water condensation from blown head gasket , too much gas . Comment: Engine oil is being burned in the combustion chamber .