Head Gasket: What Is It and What For?


Learning about the different components in your car is difficult, especially when you don’t have access to the correct information or someone to learn from. Head gaskets are a component of engines that people often know nothing about. Luckily for you, I’m here to break down what it is and what it’s for. 

A head gasket is a piece included in an internal combustion engine that forms a seal between the engine block and the cylinder head. Head gaskets are an essential component as they prevent the leak of gases and motor oil into the cylinders, which could cause issues for your vehicle. 

Keep reading to understand what head gaskets are and why they’re included in your engine. I’ll explore what can happen to your head gasket and how you can repair or replace it to get your car running smoothly. By the end of this piece, you’ll find out all you need to know about head gaskets. 

What Is a Head Gasket? 

A head gasket is an integral component in an internal combustion engine. The head gasket is a large rectangle shape with usually 3 or 4 circles cut out from it. The circles in the head gasket allow it to form a seal around the engine cylinders and between the engine block. 

What Is a Head Gasket Used For?

A head gasket is used to seal in gases and motor oil in an internal combustion engine. Head gaskets prevent leaks into the wrong areas of your engine. This helps the motor retain power and prevents the engine from overheating, which could cause severe damage to the engine. 

The head gasket prevents the cooling fluids from leaking into the cylinders in the engine. This is cause for concern as it will likely cause severe damage to other aspects of the engine, requiring expensive repairs.

Read: Why Radiator Bubbling With Cap Off?

What Causes Head Gaskets To Fail?

If you’re not a car expert or you don’t have much knowledge about vehicles, you likely discover car parts like a head gasket when something goes wrong. One important thing to be aware of is that a damage to your car’s head gasket can be costly. You may want to know what causes it to fail so that you can avoid such a situation.

Overheating causes head gaskets to fail. In the vast majority of cases, head gaskets fail after being exposed to very high temperatures for prolonged periods of time. This happens when there’s an issue with the coolant system and the vehicle overheats while driving. 

The head gasket in your car is unlikely to fail if your engine overheats immediately. However, if you continue to drive the vehicle while it’s overheating, you could cause lasting damage to the head gasket. 

Read: Why Car Overheats?

The Early Signs of Head Gasket Failure

By this stage, you’re well aware that a head gasket serves a vital role in an internal combustion engine. As a result, you’ll need to pay attention to the condition of your head gaskets to maintain your car. So what should you watch out for when assessing the head gasket condition? 

In addition to overheating, here are the early signs of head gasket failure: 

  • Tailpipe releasing white smoke 
  • Bubbling 
  • Loss of coolant 
  • Discoloration in motor oil 
  • Rough running engine 
  • Loss of power 

See below for more details about the early warning signs of head gasket issues. 

Read: Why Radiator Keeps Pushing Water Out?

Tailpipe Releasing White Smoke 

One of the earliest indications of issues with your head gasket is the tailpipe releasing white smoke. This happens when coolant is escaping through the head gasket seal and into pressurized or heated areas of the engine like the cylinder. The coolant then evaporates and is released as white smoke. 

Read: Why Is Blue Smoke Coming From The Exhaust?


Another sign that your head gasket is on the way out is bubbling. Bubbling occurs in both the radiator and coolant reservoir. This happens as compressed air escapes through the head gasket and into the radiator or coolant system. This causes bubbles as it rises through the liquid. 

Loss of Coolant 

A blown head gasket will likely leak coolant. This may cause pools of liquid to fall from the car as you drive. At the same time, the lack of coolant in the engine will cause temperatures to rise. This inevitably leads to your engine overheating when you move. Overheating can cause cracks and severe damage to machines. 

Read: Why White Smoke From Exhaust When Accelerating?

Discoloration in Motor Oil 

If you think that your head gasket could require a replacement, a good place to check is the engine oil. If your car’s engine oil has a white milky discoloration, you could have a head gasket issue. This happens as coolant leaks through the damaged head gasket into the motor oil. 

Rough Running Engine 

If your car suddenly starts running slowly and rough, it could be an early sign of head gasket issues. If your engine does not sound good when you start it up or when you’re driving, the head gasket could be the culprit. This happens as the engine is losing motor oil and can’t run smoothly. 

Loss of Power 

A damaged head gasket can cause your engine to lose power as you drive. This is because the head gasket contains pressurized air from the car cylinder. If this air escapes through a faulty seal, the cylinders will lose pressure. When the cylinder loses pressure, it can cause the engine to lose most if not all of its power. 

What Happens When a Head Gasket Fails?

When a head gasket fails, the engine will lose power while driving. Alternatively, the engine would overheat, which poses a risk of severe damage to the engine. As a result, the head gasket will need to be repaired or replaced to restore your vehicle to working condition

How Much Does It Cost To Replace a Head Gasket?

It costs between $1,500 and $2,000 to replace a head gasket on a car. A large proportion of the cost goes on labor expenses as the engine will need to be disassembled to remove the damaged gasket. This is a time-consuming process that drives up the labor costs. 

Purchasing the parts needed to replace a head gasket can also fetch a high price. Typically, the components required for this repair will cost you $700 to $800 depending on the make and model of your car. The exact costs of repairs will vary depending on what you drive and where you live, as labor costs are higher in certain areas. 

Can You Repair a Head Gasket? 

Replacing the head gasket on your car can be an expensive endeavor. If you have an old car that’s not worth a lot of money, replacing the head gasket could cost more than the car is worth. As a result, you may search for a way to avoid paying for a replacement by repairing the damages. 

You cannot repair a head gasket in most cases after it’s been damaged. Once the head gasket has been damaged, you’ll most likely require a professional repair at a mechanic. However, you can use sprays to seal the gasket head, which will provide a temporary fix. 

Once your head gasket is blown, you should stop driving the car immediately. If the damage is minor, you can use a head gasket seal spray. However, if the damage is severe, the vehicle will require a likely expensive repair. 

Can You Prevent Head Gasket Damage? 

You can prevent head gasket damage by correctly maintaining the coolant system in your car. Most head gasket damage is due to overheating in the engine. A well-maintained coolant system will keep temperatures at a safe level and protect the head gasket against overheating. 

To maintain the coolant system, get your mechanic to examine the condition of the coolant system during the vehicle’s annual service. On top of this, keep the coolant levels topped up with the manufacturer’s recommended coolant mixture. This prevents damage to the system and keeps you safe from overheating damage. 

Final Thoughts 

The head gasket is a component in an internal combustion engine. It forms a vital seal between the cylinders and engine block. The head gasket also keeps coolant, compressed air, and motor oil contained in the appropriate location. When it fails, the engine could lose power and overheat. 

In most cases, repairing a head gasket is not practical, if not outright impossible. As a result, you’re better off paying for a replacement. A head gasket replacement will cost you well over a thousand dollars, and this price could rise depending on where you live and the make of your car.

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