Here's why:
* Combustion gases and coolant mix: A head gasket leak allows coolant to enter the combustion chambers. When the engine burns the fuel-air mixture, this coolant is turned into steam, which then exits through the exhaust. You'll see white, milky smoke or steam coming from the exhaust, especially when the engine is cold or first started.
* Other possibilities (less likely): While less common, a cracked cylinder head or cracked engine block could also allow coolant to enter the combustion chamber.
What you should NOT do:
* Continue driving the vehicle: Driving with a head gasket leak can cause catastrophic engine damage. The overheating and lack of lubrication can quickly ruin your engine.
What you SHOULD do:
* Inspect the coolant level: Check your coolant reservoir. If it's low, this strongly points to a leak.
* Check the oil: Look for a milky, mayonnaise-like substance on the oil dipstick. This indicates coolant mixing with the oil – a very bad sign.
* Have it diagnosed by a mechanic: This is crucial. A mechanic can perform a proper diagnosis to pinpoint the source of the leak and recommend the necessary repairs. They may perform a compression test, a leak-down test, or other diagnostics to confirm the problem.
Ignoring this problem will likely lead to a much more expensive repair later. Get it checked as soon as possible.
