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Can You Drive with a Blown Head Gasket?

Can You Drive with a Blown Head Gasket?

The head gasket is a small, but important part of your car. 

It forms the seal between the engine block and cylinder heads. It is a serious issue if it fails, but can you drive with a blown head gasket? 

Driving with a blown head gasket is not recommended as doing so can result in severe engine damage from coolant leaking into the engine block. Continuing to drive the vehicle in this state could result in a complete engine rebuild.

Keep reading to learn more about the repercussions of driving with a blown head gasket!

Is It Safe To Drive With a Blown Head Gasket?

To answer this question, it is important to understand what a head gasket is and what it does. 

Your engine is a complex system, and it has many fluids and gases that circulate through it during the combustion cycle. 

In a water-cooled engine, combustion gases, cooling, and lubricating oil must circulate to keep the engine from overheating and to make it run efficiently. Each of these fluids runs in a separate circuit.

It is critical that these gases and liquids do not combine!

The head gasket is the seal that prevents pressure loss, and it keeps everything in its place. A leak in the head gasket can result in combustion gases escaping, loss of coolant, or contaminated oil. 

Head gasket leaks can be either internal or external. An external leak can be seen as oil or coolant on the outside of the engine.

You can usually see it underneath the engine, where you might find a wet spot underneath the car when you move it. 

An internal leak is when the combustion gases and coolant leak inside the engine, but nothing is escaping to the outside. You can have coolant leaking into the oil system or the other way around. 

If coolant leaks into the combustion chamber, the fuel will not burn properly. When combustion gases escape from the cylinder through the head gasket leak, it will reduce the effectiveness of the cooling system. 

The severity of the leak and the symptoms that it causes depends on where the leak is located, how bad it is, and which component of the system is interacting with other components or escaping. 

How Long Can You Drive With a Blown Head Gasket?

The answer to how long you can drive with a blown head gasket is that you really shouldn’t be driving it at all with a blown head gasket. It’s true that the car might still run, but getting stranded is in your future if you do! 

Ultimately, it boils down to how big the hole is and where it is located.

A small amount of white smoke coming out the tail end might mean that you can drive it to the repair shop, but you should not. If your engine is running rough or overheating, then it is headed for complete failure soon. 

There is no easy answer as to how long you can drive around with a blown head gasket because it depends on many factors.

The only thing you do know is that the longer you drive, the more likely it is that you will have a catastrophic failure of the engine or another major component.

Does a Blown Head Gasket Ruin an Engine?

A blown head gasket can ruin an engine in a short time. One of the causes of damage is if coolant enters the combustion chamber. 

This compromises the complete combustion of the fuel and reduces the performance of the engine. This causes steam to come from the exhaust, which can look like white smoke. 

The steam can damage the catalytic converter. If a large amount of coolant enters the engine, it can suffer from “hydro lock.” When this happens, a gas volume that is greater than the volume of the cylinder. 

If this occurs, it can bend the cylinder rod and destroy the engine. 

If the problem is combustion gases leaking from the engine, then the engine will lose power and run rough.

The loss of pressure will compromise the ability of the cooling system to do its job and will cause the engine to overheat. Another thing that can happen is that the gases can escape into the coolant and cause air pockets. 

If you find that coolant is leaking into the oil and causing the milky texture, then the oil cannot do its job of keeping the engine components from grinding together. This can cause the engine to overheat and parts to wear out more quickly. 

The bottom line is that even a minor leak will ruin the engine and cause damage over time.

Depending on where the leak occurs and what liquids and gases are involved, the damage can be immediate and severe. Even if the car still starts and runs, if you see any of these signs, it is best to stop driving it until you can get the head gasket replaced.

If you have a blown head gasket, it is not a question of whether it will cause engine damage, but it is one of when and how bad it will be when it does occur. 

The problem will not get better on its own, and even if you use products to stop the leak, these only work temporarily. The sooner you get the head gasket fixed, the less expensive it will be because less damage will have occurred. 

How To Know You Have a Blown Head Gasket?

Depending on where the leak is and what liquid or gas is escaping, the symptoms can be different. Blue smoke from the exhaust means that oil is making its way into the combustion chamber. The exhaust will smell like burning oil.

 The source of the oil can be another issue, but it can also be a blown head gasket. 

White smoke coming from the exhaust can indicate that coolant is making its way into the combustion chamber. If coolant is leaking into the oil system, the oil may look like mayonnaise or a chocolate milkshake. You can check this by examining the oil on the dipstick or filler cap.

The head gasket is not always the source of contaminated oil, coolant, or oil entering the combustion chamber.

These issues can be happening in other parts of the system, but if you see them, a blown head gasket should be one of the first things you suspect. Another thing that may occur is wet spark plugs.

If you take the car to a mechanic, they will perform a compression test to find out if the engine is maintaining proper pressures during combustion.

Once the engine is cool, they might also take the radiator cap off and start the car. 

If the coolant foams or bubbles, it can be a good indicator of a blown head gasket. 

A blown head gasket always gives you signs. If it is a tiny leak, sometimes the signs may be so subtle that you do not notice them. 

As time goes on, it will only get worse, and eventually, you will have no choice but to notice it.

How Much Does It Cost To Replace a Head Gasket?

Many factors determine the replacement costs of a head gasket. The make and model of your car affects cost the most. Head gasket replacement cost is broken down into the actual cost of the replacement part and labor. 

The type of engine impacts how difficult it will be to replace the head gasket and the labor cost involved.

Also, you have many choices when it comes to head gaskets. The type you choose will also have an effect on the replacement cost. 

Here are the most common types that you will find.

  • Multi-layer steel
  • Solid copper
  • Composite
  • Elastomeric
  • O-ring

According to national averages, it generally costs between $1,624 and $1,979 for most makes and models of cars.

The part itself costs between $715 and $832. Labor usually runs between $909 and $1,147.

Fortunately, modern head gaskets are long-lived. Many of them can be expected to last at least 10 years. 

Depending on the vehicle you own, and how well you take care of it, they have been known to last as long as 15 or more years.

A blown head gasket is typically a result of repeated overheating of the engine. If the car is overheating, and you continue to drive it, then it can cause the head gasket to blow. 

A failure in any part of the cooling system can cause damage to the head gasket.

The best way to prevent a blown head gasket is to keep your oil changed, make sure your cooling system is in good condition, and have regular service performed on your vehicle. 

The best time to catch these types of problems is before they occur. Good routine maintenance is one way that you can help avoid a more expensive repair bill later.

Now you know what a head gasket is and why you should never keep driving if you suspect that this has happened. Even if the car still runs, you are only causing more damage by doing so. 

If you see any of the signs listed in this article, you should pull over to a safe location and have your car towed to a mechanic who can fix it as soon as possible. 

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Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!