A blown head gasket has several symptoms that include overheating, cloudy oil mixture and white smoke blowing from the tailpipe. Once the head gasket is blown it will need to be replaced. However, there are commercial products that offer short-term fixes for smaller leaks.
A head gasket's purpose is to seal the engine block and cylinder head. It keeps in the pressure for the internal combustion process and blocks the oil and coolant from mixing together. The gasket has to stay compressed between the two parts of the engine to ensure the pressure of the engine block stays the same.
Causes of Head Gasket Failure
The head gasket can fail for a number of reasons, but the most common cause is overheating, which, ironically, can also be a symptom attributed to a blown head gasket. When an engine overheats the cylinder head and block can expand. This can warp the mating surface area of the block and pinch the seal. Once this occurs the coolant will be lost from the system. Loss of coolant will result in the engine burning what is left over, resulting in white smoke expelling from the tailpipe.
Pre-ignition occurs when an engine's timing is off. When the timing is off the combustion pattern does not occur correctly. This results in the pistons and valves functioning at separate intervals, which will cause them to collide. The pressure from this will then lead to a blown head gasket.