As you know, the number of vehicles is increasing day by day. Now, drivers demand high-performance engines in new cars. That’s why research says global head gasket market will grow at a compound annual growth rate of 13.2% between 2026 and 2033.
This growth shows the importance of this mini device. If you want to know what a head gasket is, you can read this article. We explained head gasket types, purpose, failure, symptoms and replacement cost in this guide.
What is a Head Gasket in a Car?
Head gasket is an important part of combustion engine which is used to seal the area between engine block and cylinder head. Basically, its main goal is to prevent gas and coolant leakage. In this way, head gaskets maintain the overall performance of engine.
Head gasket material is selected on the base of heat & pressure resistance. Mostly, multi layer steel, solid copper, graphite composites and steel core laminates are used to manufacture durable head gaskets for your cars.
How Does a Head Gasket Work?
As you know, the head gasket is present between the cylinder head and engine. So, when your engine burns the fuel and air inside the cylinder, the gasket seals it to stop the leakage of combustion pressure.
Your vehicle’s engine has coolant, which flows through different hoses to cool down the system. The head gasket provides a leak-proof path, so they do not mix with your engine oil.
Furthermore, engine oil hoses also carry oil to lubricate other components of the car. In this case, this mini gasket seal keeps the oil separated from the coolant and the combustion chamber.
Head Gasket Types You Need To Know
1. Multi Layer Steel Gasket
If you notice in depth, newly updated cars use MLS gaskets. Actually, it uses two to five thin layers of steel. In between these layers you often find rubber layers or thermoplastic films. These layers reduce noise & control vibrations.
The outer layer of the head gasket, which touches the engine is also coated with a special rubber-like material viton. This layer sticks the gasket to metal surfaces to provide you with a strong blockage. This is the best choice for your high-compression engines.
2. Solid Copper Head Gasket
This type of gasket is made up of a flat sheet of copper. Well, copper is famous for its strong heat resistance. For this reason, copper gasket is used in racing & powerful street cars. This gasket uses a special process called O-ringing. In this process, a small groove is made around the cylinder.
Then a thin metal wire is placed inside this groove. Therefore, when you tighten up the cylinder head, the wire gets pressed into the copper gasket. You use this gasket seal in turbocharged, supercharged engines and normal engines.
3. Composite Head Gasket
These head gaskets were used in older vehicles as they were manufactured in the 1980s. They are an affordable option for you but have more chances to blowout comparatively. Basically, asbestos or graphite is used to make this type of gasket.
This is why they have the ability to seal the engine parts even when the surface is rough or not smooth. But in present days asbestos is banned due to health safety reasons. Due to this reason, now other safe alternatives are used to produce head gaskets.
4. Elastomeric Head Gasket
You find steel cores in these head gaskets. This core is lined up with small elastomeric silicone beads. Which are created with silicone rubber, silicone foam, silicone sponge or fluorosilicone.
So, the material enhances the strength and durability of the head gasket. Furthermore, they have the ability to bear compressive forces, that’s why they form a tight seal around the leakage points.
5. O-ring Head Gasket
If you need very high clamping pressure, then the O-ring gasket is best for you. This is because the O-ring has a small contact area. When you tighten the engine parts you build more pressure on this small area. In addition, you can reuse them if you handle them in the right way.
| Gaskets | Lifespan | Failure risk |
| MLS | Longer life | Low, if you install with a smooth surface finish |
| Solid Copper | Very durable | Very low risk, but needs precise installation and torque |
| Composite | Short life | Very high and more prone to blowouts under heat/pressure |
| Elastomeric | Durable | Under compressive stress |
| O ring | Longer | Low risk, plus reusable but difficult installation |
What is the Purpose of the Head Gasket?
Well, in a water-cooled internal combustion engine, mainly three fluids travel between the cylinder block and the cylinder head. So, the core job of the head gasket is to keep them separate. These three fluids are:
- Coolant in different types of hoses
- Oil in the lubricating parts
- Combustion gases in each cylinder
So, the engine requires these three liquids at their correct positions to do its job in the right way. They must not leak or lose pressure. At this spot, the head gasket fulfills these goals for the high performance of the engine.
Common Head Gasket Failure & Its Symptoms
What are the first signs of a blown head gasket? There is no single sign that can tell you that the head gasket is faulty. Below we will discuss various signs of a non-functional head gasket.
- Blue Smoke From Exhaust: This sign shows the failure of oil leakage. It tells you, oil is entered into the combustion chamber.
- Milkshake Color in Oil: If coolant is leaking into the oil system then this symptom informs you about the real problem. You should confirm it on a dipstick or oil filler cap. But this sign is not always shown due to the defective head gasket. Because the oil can be leaked from the other routes as well.
- Power Reduction/Rough Drive: This happens when the combustion gasses leak from the cylinder. Due to this leakage compression loses and causes rough running of your vehicle.
- Engine Overheating: This is another situation where the same gas leaks into the cooling system. So, the cooling system gets affected and reduces its performance which results in overheating of the engine.
- Air Bubbles in Coolant: In some cases, the leaked gas gets trapped into the small spaces between the gasket, engine block plus cylinder head. And then it escapes when the engine turns off. In this way, these gasses create air pockets in coolant. Sometimes, the coolant can move out from the coolant tank.
Head Gasket Testing Before Repair
How to check gasket failure? If you want to repair failed head gasket then you can perform following basic methods to confirm the problem.
Chemical Check: This is a very easy test you have to mix the coolant of your vehicle with the blue liquid (bromothymol). If the liquid turns yellow from blue, the gasket is damaged.
White Smoke From Exhaust: Continuous white smoke with a sweet smell means the coolant is leaking into your combustion chamber. Another reason can be the presence of coolant in the cylinder. This condition can reduce the performance of the engine of your car. Even the engine can face hydrolock.
Pressure Gauge Test: You can attach pressure gauge with the radiator and provide required pressure. If the pressure gauge drops down suddenly the gasket is blown.
Leak Down Inspection: For this technique, you have to join the leak down tester with each cylinder and check their pressure. A faulty head gasket is identified if the pressure goes above 15%.
Head Gasket Replacement Cost
Head gasket: how much to fix? The price of a head gasket is not too high. But its labor cost can charge you more. The reason is its time consumption due to the removal & replacement of the cylinder head. If we talk about its average repair cost it ranges between 1000 to 2000 dollars.
| Replacement components | Approximately cost |
| Head gasket valve cover replacement cost | $100 to $500 part plus labor |
| Cost to fix intake manifold gasket leak | $300 – $1000 |
| Exhaust manifold gasket replacement cost | $150 and $500 |
| Head gasket oil leak repair cost | $600 to $1000 |
What to expect after head gasket replacement? If the head gasket is replaced successfully, your car must run smoothly & the engine should perform well. Plus, the car should hold a normal operating temperature and you see clean exhaust smoke.
FAQs
Which Are Small Head Gasket Leak Symptoms?
If you see escape signs of coolant, sweet smell from engine, bubbles in coolant or rough start, bad head gasket can be a reason. If you want to read real experiences of head gasket blown symptoms read this Reddit post.
How to Fix a Faulty Head Gasket Without Replacing it?
Sometimes, you do not have enough money for the fixation of head gaskets or absence of experienced workers. At such a time, you use a chemical “Head Gasket Sealer”. Like, steel seal, k seal & bar’s leak. Personally, I would recommend you steel seal to fix head gasket leakage.
What Causes a Blown Head Gasket?
The primary cause of this can be the overheating of the engine because an over heated engine can damage the seals. Moreover, high combustion pressure may also result in blown head gaskets.
Do You Use Gasket Sealer on Head Gaskets?
No, most mechanics do not recommend it when installing a new head gasket. Because modern gaskets, especially multi-layer steel, are pre-coated with their own sealing material. So, the additional layer can create an uneven surface. It totally depends on the type of head gasket.
When to Replace Head Gasket?
You can predict the replacement needs of the head gasket from its failure signs. So, if your car shows symptoms that warn that your head gasket is leaking, you must replace it.
Final Words
Head gasket is a significant component of our car engines. Because it provides a secure path for gas and liquid to move around the engine & other areas. If the head gasket wears out and you ignore this, it will result in bigger expenses as it can damage other parts as well. Hence, you must change the gasket seal if you see even a minor issue or leakage in it.
