One of the most important seals of any car engine is the head gasket. This joint between the engine block and the cylinder must contain the combustion force inside the cylinder. It also seals a large number of coolant passages and undergoes large temperature changes as the engine cools and heats up. If the head gasket is damaged, it can cause minor or major problems that can lead to engine failure. Most symptoms of a damaged head gasket can be diagnosed through careful examination, and problems can be confirmed with specialized tools before taking the car in for an expensive, time-consuming repair.
Pressure loss
One of the areas of failure can be the seal between the engine cylinder and the coolant line. When the refrigerant heats up and the pressure rises, it will be forced into the cylinder during charging. The refrigerant will quickly turn to a gaseous state during combustion and will be seen as a white cloud coming from the exhaust pipe. This cloud of vapor will be much thicker than what is usually seen in cold weather and will also have a sweet smell similar to antifreeze. To determine the exact cylinder, two tests can be performed. Visually inspecting the spark plugs will eventually show that one is wet or clearly cleaner than the rest. A pressure gauge will show lower pressure in the damaged cylinder.
Air in the cooling system
Like the problem of the coolant in the cylinders, the air in the coolant is also caused by a failure of the head gasket between a cylinder and a cooling duct. This usually happens at the same time that the coolant leaks into the cylinders. Symptoms to look for faster are overheating and low cooling with no obvious filtration. However, these symptoms also occur for reasons other than the burned head gasket and other tests are needed to confirm the problem. Test kits are available at many auto parts stores. The kits will show if there are tailpipe gases in the gasoline engine coolant and pressure tests will show lower pressure in the leaking cylinder.
Oil in the coolant
Sometimes the cylinder head gasket will be damaged so that the engine oil will enter the cooling system. Since this is not likely to affect performance, symptoms may not be detected until a long time later. A regular coolant check is the best way to detect the problem before major engine damage occurs. If any oil has mixed with the refrigerant, it will have changed color, to a light brown, like that of coffee with lots of milk.
Refrigerant in oil
Coolant entry into the oil system is one of the most common head gasket problems and one of the most damaging to the engine. As with oil in the coolant, you may not notice any change in engine performance and a burned head gasket goes unnoticed for a long time. It is usually discovered during oil changes. The most severe cases cause the oil to become very thick and lumpy and light brown in color. However, it is more difficult to find minor problems. Symptoms occur much earlier in unstable arms. Look at the bottom of the oil cap and tube and look for the same mixture of thick brown oil.
Refrigerant leaks
You may also see a damaged head gasket that only causes a coolant leak. The first symptoms are overheating and pools of coolant on the ground. A thorough examination of the exterior of the engine can show the location of the leak. However, there are many other areas on an engine that tend to leak coolant and it can be difficult to determine the source. This is especially true of older engines that have accumulated a lot of dirt. An UV test kit can help better locate the source of some leaks; These kits are available at most auto parts stores.
Pressure loss
Sometimes a gasket can fail and cause a cylinder to lose pressure. The first indicator of a damaged head gasket is the sound of hissing or small knocks that can be difficult to locate as they sound like an unstable arm. The most serious cases can lead to an obvious loss of power in the motor. Depending on its location, you may see the air leak in the engine. The most reliable test for this problem is a pressure gauge.
