Common Symptoms:
* White smoke from the exhaust: This is a classic sign, indicating coolant is leaking into the combustion chamber. The smoke might be especially noticeable when the engine is cold or under load.
* Overheating: The coolant is leaking, reducing the engine's ability to cool properly. You might see the temperature gauge climb rapidly, or the engine overheating warning light illuminate.
* Low coolant levels: Regularly checking your coolant reservoir is essential. A significant drop in coolant level, without any visible leaks, points towards an internal leak like a blown head gasket.
* Oil contamination: Coolant leaking into the oil will make the oil look milky or have a mayonnaise-like consistency (emulsion). This is a very serious problem requiring immediate attention.
* Coolant in the oil: Check your dipstick regularly for signs of milky oil.
* Loss of compression: This can lead to a loss of power, misfires, or difficulty starting the car. This is often a later stage symptom.
* Sweet smell from the exhaust: Coolant has a slightly sweet odor. Detecting this in the exhaust is a clue.
* Bubbles in the coolant reservoir: If you see bubbles in the coolant reservoir when the engine is running, this suggests combustion gases are entering the cooling system.
Important Note: Some of these symptoms can be caused by other problems (like a cracked cylinder head, leaking radiator, etc.), so it's important not to jump to conclusions. A proper diagnosis by a mechanic is needed to confirm a blown head gasket. A compression test and a leak-down test are usually performed to definitively diagnose a blown head gasket.
