One of the most popular phrases is a ‘blown head gasket,’ and it spans car culture and into everyday phrases. Many people use the phrase to call someone crazy or to say that they are really upset, but when in relation to cars, the term can signal an expensive fix. It’s important to know what they are, how to determine if you’ve blown one, and what steps are possible to prevent the problem.
What Is a Head Gasket?
A head gasket is a mechanical seal that is sandwiched between the cylinder head(s) and the engine block. It has two purposes. The head gasket is part of the combustion chamber, which helps to contain the combustion process, ensuring that the engine runs smoothly. It is also a physical extension of your fluid passages to the block from the head. Oil, fuel, and coolant all have different purposes and must be separated, though they must also operate in a small space.
Because the head gasket is so close to the combustion area, it must be durable and tough. Many gaskets are made of steel or composite materials, though copper is primarily used for high-performance applications. Despite the fact that this component is so critical, head gasket sets can be affordable. Most of the costs associated with replacement are caused by the extensive labor required to remove the cylinder head.
Symptoms of a Blown Gasket
One of the most obvious signs of a blown head gasket is that coolant leaks from the exhaust manifold. The gasket failed along the outer portion, so water is leaking out from the engine to the outside.
You may also notice white smoke coming from the exhaust pipe, which signals that the water is leaking internally, so coolant is passed into your hot combustion chamber. What you see from the tailpipe is burned glycol and steam. Your engine may continue to operate normally, at least until all the coolant is gone.
Sometimes, however, the gasket doesn’t leak fluid outside the engine or into the combustion chamber, so you may not notice that fluid is burning. However, you can still tell you have a problem because your coolant levels run low, but you can’t find a leak. Therefore, it’s a good idea to check the fluids periodically.
If you have coolant that has burned away or leaked, it’s likely that there isn’t much left in the reservoir to cool the engine, so it could overheat. Most modern cars have a warning light system in place to let you know the engine is overheating long before it does significant damage.
It’s also possible to see bubbles in the overflow tank or radiator. This happens when your head gasket failed between the water passage and combustion chamber. Air is forced into the cooling system, which causes bubbles. It’s more serious than you may imagine because the bubbles can cause an air pocket, which doesn’t let coolant pass.
While the cost of replacement and the symptoms can both be a little unnerving to car owners, you can prevent head gasket failure by making sure the engine doesn’t overheat. You should check oil levels, radiators, and overflow tanks as recommended in your manual. You should also add coolant when needed and make sure that you watch for unexplained fluid loss.
It’s also a good idea to check your radiator hoses for frays and splits and replace them the moment you see damage.
You should also watch for leaks and unusual smoke. Even if you follow all the preventative measures, your head gasket can still fail, so if you notice any of the symptoms mentioned earlier, take them seriously and get it replaced as soon as possible.