The cylinder head, and other parts, expand as they heat up. That can cause a symptom at one time and not others, but typically that doesn't stay that way for very long. Using a quart of oil in three months is common and not a cause for concern, but if you're seeing white smoke, you should also be losing coolant. If you're not losing coolant, you may be seeing water vaporizing that condensed in the exhaust system that last time you ran the engine. Water vapor is one of the byproducts of a properly-working catalytic converter and is why you'll normally see water dripping from the tail pipe or drain hole at the back of the muffler.
Your mechanic can perform a chemical test at the radiator to verify a leaking head gasket, but given the intermittent nature of the symptoms, that test must be done when the symptoms occur. That might mean leaving the car there overnight so the engine will be cold when the test is done. This involves drawing air from the radiator through a glass cylinder with two chambers partially-filled with a special dark blue liquid. If combustion gases are present, the liquid will turn bright yellow.
All engines today use some oil between oil changes. To address the many complaints dealers were getting, you'll find your dip stick marked with "min" and "max" now instead of "add" and "full". As long as the level stays above the "min" mark, there's no need to add any oil.
Thursday, April 16th, 2015 AT 7:37 PM