What Causes A Blown Head Gasket?

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A head gasket is an important part of your vehicle’s cooling system, a seal that sits between the engine block and the cylinder head. The head bolts attach them, help the head gasket prevent coolant from leaking into your engine and protect the cylinders from overheating.

In addition, the head gasket seals the combustion chamber, which prevents hot combustion gasses from escaping and causing a fire hazard. For your vehicle to run at its best, it’s important to keep this seal in good condition by regularly checking for leaks, cracks, or other signs of deterioration.

Head gaskets are usually made out of rubber or silicone-based material. They are installed in the cylinder head and then sandwiched between two steel surfaces for a tight seal. A head gasket can be made out of one piece or several pieces that form a seal inside the cylinder head.

A blown head gasket is when an internal combustion process leaks in the cooling system. Pressure, overheating, poor design, or age are the major causes.

Here are some of the most common causes of a blown head gasket that will be discussed further in the article:

  • Coolant leaks occur when coolant seeps into the engine heat and mixes with the oil.
  • Overheating is caused by a stuck thermostat or air leak in the cooling system.
  • Oil leaks contaminate the level of coolant, causing it to break down and leak into the engine.

Let’s find out more about a blown head gasket.

Main Causes of a Blown Head Gasket

Head gasket issues or failures are common in engines with aluminum heads and blocks. A faulty head gasket can cause major problems with your car’s performance and may even lead to engine failure. It is a serious issue that needs attention as soon as possible. Here are five causes of having a blown head gasket so you can diagnose the problem and get it fixed instantly.


The head gasket is a thin metal or rubber seal that separates the engine block and the cylinder head. It ensures no coolant, oil, or air gets into the combustion chamber, negatively impacting the combustion process. When a car overheats, it can cause pressure to build up in the cooling system, forcing coolant out of the radiator fan and into the cylinder head.

It will eventually cause a blown head gasket because when it mixes with oil and air, it creates an explosive mixture that will blow out the head gasket. If your engine overheats, it causes the metal to warp and break down, leading to poor performance, engine damage, and even engine failure, which is one of the warning signs.

Pre-ignition and Detonation

Pre-ignition and detonation are two different types of engine malfunctions. Pre-ignition is when a spark ignites the air/fuel mixture in the cylinder before the piston reaches Top Dead Center. It can happen due to an overly lean fuel mixture or a too high engine speed.

Detonation damage is when the air/fuel mixture in the cylinder is ignited by extreme heat and pressure waves created by a flame front traveling through the unburned charge. It is usually caused due to over-advanced ignition timing, excessively low octane fuel, or excessively high compression ratio.

High Mileage and Age

High mileage and age are two major factors that can cause a blown head gasket. The higher the mileage on your car or truck, the more likely you will experience problems with your head gaskets. Age also plays an important factor because as your engine ages, it will wear down from all the miles you’ve put on it.

Insufficient Oil

Lack of oil in the engine is another common cause of a blown head gasket. If you don’t put enough oil in your engine, it will seize up and blow out your head gaskets. The oil in the car circulates throughout the engine and lubricates all its parts. Therefore, an issue with the head gasket can cause an oil leak, leading to oil contamination in other parts of the engine.

Incorrect Installation

Incorrect head gasket installation can also lead to a blown head gasket. Even though installing a head gasket is straightforward, some pitfalls can lead to an unsuccessful installation.

There is a possibility that the mechanic may not have torqued all the bolts to their exact specifications or may have used a sealant that did not provide enough protection for the engine. The incorrect installation can cause a coolant leak within the engine, severely damaging your car’s performance and leading to costly repairs.

gear4wheels1-20nt of the cylinder head gasket in the car engine.

How to Prevent Head Gasket Failures?

The head gasket is a vital component of the engine; when it fails, the engine will not work. Hence, to prevent head gasket failure, you should check your coolant level regularly in the coolant reservoir and ensure that it never gets too low. If you notice any leaks in your cooling system, you should take your car to a mechanic as soon as possible to have them repaired.

There are a few different options for repairing the head gasket, but one of the most popular options is replacing it entirely. While it can be expensive, it also ensures that you will not have any more issues with your car in the future.

Moreover, ensure that you use appropriate engine oil for your vehicle. Get regular oil changes and stay on top of maintenance checks so that you don’t have any major problems down the line. It will also help if you avoid driving too fast and keep your tires inflated.

Furthermore, you should check for any damage or leaks in the clogged radiator hoses. However, avoiding overheating your engine is the ideal way to prevent head gasket failures. Finally, don’t forget to remove all the dirt, grime, or debris from the head gasket area of your car’s engine block by wiping it down with a clean rag or paper towel.

If you live in a hot climate or drive long distances, you should ensure that your cooling system is in good condition and that you have enough coolant passages in the aluminum radiator. You should also avoid over-revving your engine by keeping it under 4500 RPMs when driving on the highway.

Lastly, ensure you have enough compression by replacing worn-out parts like spark plugs and air filters as soon as possible. All these pro tips can help you prevent and resolve unexpected head gasket issues.


In many cases, the signs of head gasket failure are often not obvious. The best way to determine if you have a blown head gasket is to check for oil in your coolant or see if white or blueish smoke is coming from under your car’s hood or the exhaust pipe. Also, notice if there is whitish milky sludge in the engine oil, acrid smoke, or bubbling in the radiator.

Always remember that driving with a blown head gasket is not recommended, as it can cause a lot of damage to the engine. Moreover, it leads to more serious issues such as rough idling and loss of power. Therefore, the best thing to do when you have this problem is to get your car checked out by a professional technician or mechanic nearby.