* Head Gasket Failure: This is the most common culprit. A blown or leaking head gasket allows coolant to enter the cylinders, mixing with the combustion process and producing white, steamy smoke from the exhaust. You might also see milky oil (oil that looks like a milkshake) on the dipstick or a loss of coolant without any visible leaks.
* Cracked Cylinder Head: A crack in the cylinder head can also allow coolant to leak into the cylinders. This is often accompanied by other symptoms like overheating or low compression in one or more cylinders.
* Cracked Engine Block: Less common, but a cracked engine block can also cause coolant leakage into the cylinders. This is usually a very serious and expensive repair.
* Warped Cylinder Head: Overheating can warp the cylinder head, causing it to no longer seal properly against the head gasket.
Important Considerations:
* Sweet Smell: If the white smoke has a sweet smell, this strongly suggests coolant. Exhaust smoke from burning oil usually has a different, more acrid smell.
* Amount of Smoke: A small amount of white smoke on a cold start, especially in humid weather, might be condensation. However, persistent or heavy white smoke is a problem.
* Other Symptoms: Pay attention to other symptoms like overheating, loss of coolant, milky oil, low engine power, or rough running. These can help pinpoint the cause.
What to Do:
Do not continue driving the car if you're seeing persistent white smoke. Driving with a coolant leak can cause severe engine damage. Get the car to a mechanic immediately for a proper diagnosis and repair. Ignoring the problem could lead to a costly engine rebuild or replacement.
