* Head Gasket Failure: This is the most likely culprit. A blown head gasket allows coolant to mix with the engine oil and/or enter the combustion chamber, resulting in white, steamy exhaust. You might also notice milky oil (oil that looks like a milkshake), overheating, or low coolant levels.
* Cracked Cylinder Head: Similar to a blown head gasket, a crack in the cylinder head allows coolant to leak into the combustion chamber. This is often accompanied by other symptoms like overheating and low coolant levels.
* Cracked Engine Block: Less common than a head gasket or cracked cylinder head, but a crack in the engine block can also lead to coolant entering the combustion chamber. This usually involves significant damage and is often accompanied by major coolant loss.
* Coolant Leak into Intake Manifold: A less frequent cause, but a leak in the intake manifold can introduce coolant into the combustion process, leading to white smoke.
Less Likely, but Possible Causes:
* Worn Valve Stem Seals: While more likely to cause blue smoke (burning oil), severely worn valve stem seals *could* contribute to some white smoke if coolant is also present.
Important Note: White smoke that smells sweet is a strong indicator of coolant burning. White smoke that smells like burning oil points to a different problem (likely oil burning).
What to do:
Do *not* continue driving the car with white smoke coming from the exhaust. This could cause significant engine damage. Have it towed to a mechanic for diagnosis and repair. The underlying problem needs professional attention to prevent further damage and potentially costly repairs.
