Rubber Gasket

How to Tell If You’ve Got a Blown Head Gasket

Most engines have a four-stroke design that uses the motor oil, water coolant, and combustible air fuel. These fluids can never come into contact, and the engine needs to be well-routed between components to ensure that there’s no intermixing. This is where the gasket comes into play.

What is a Head Gasket?

brand new gasket

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A head gasket is a component between the cylinder head and the engine block. Most cars have a gasket, but they may differ in their construction and thickness depending on the manufacturer’s engine design.

The component plays a critical role as it seals the combustion chamber, which contains exhaust gases and allows the car to build compression to help in maintaining the engine’s efficiency. Also, the gasket works to keep the oil and coolant out of the combustion chamber.

The gasket goes through varying temperatures due to its position between hot and cold engine components. It has to face the cold temperatures from the cooling system and the high heat from the combustion chamber.

With time, the range of temperatures can take a toll on the gasket, leading to marks along the surface. Furthermore, the gasket may begin leaking, and if this worsens, the gasket can blow.

Why do Gaskets Blow?

damaged casket

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The gasket has to tolerate the high-pressure combustion gas and the engine coolant which can have cold ambient temperatures. Over time, the gasket may leak. Unfortunately, gaskets blow regardless of the make or model of your car.

You can’t see the gasket on a car with the engine installed as it seals the coolant passage from the combustion chamber and the atmosphere. It’s for this reason why you may not realize that you have a blown gasket.

Furthermore, it can be a challenge to diagnose the symptoms of a blown gasket. You need to know which other signs could indicate a gasket problem as you cannot be able to inspect a gasket leak.

Sings of a Blown Gasket

Some of the signs you may notice if you have a blown gasket include:

  • Overheating engine
  • White smoke from the tailpipe
  • Bubbles in the radiator
  • Coolant leaking from the exhaust manifold
  • Low cooling system
  • Fouled spark plugs
  • White milky oil

Overheating Engine

If you notice that your engine overheats after a long drive, you may have a blown head gasket. This can be because of a lack of coolant, or the vehicle’s radiator is unable to cool the coolant.

An overheated engine can lead to the expansion of metal components, which can lead to warping and cracks. Also, it can damage seals, leading to other leaks in the engine. You’ll need a full engine rebuild to fix these problems.

White Smoke from the Tailpipe

Most leaks occur internally, allowing the coolant to get into the combustion chamber. The coolant could either evaporate or burn with the combustion process; this is what causes the white smoke from the tailpipe.

The smoke continues when the engine is warm. A significant leak could lead to excess smoke coming from the tailpipe.

Bubbles in the Radiator

Internal gasket leaks not only allow coolant into the combustion chamber, but it also allows exhaust gases into the coolant. You may notice what looks like the coolant boiling even when it’s cold. These bubbles are exhaust gases that push their way into the cooling system.

Fortunately, you can carry out a test to determine if there’s a presence of exhaust gases on your coolant. The test can indicate a blown gasket.

Coolant Leaking from the Manifold

An internally leaking gasket could cause the coolant to come from the exhaust manifold or below the intake. This occurs when the engine is warm. If your car doesn’t have a hose or a cooling passage near the gasket, this could indicate a gasket leak.

Low Cooling System

You can tell that you have a blown gasket when you pressurize the cooling system. Watch out for any pressure loss as this could show that there’s a leak from your gasket. While this may only be an indication, it’s not conclusive enough to prove that you have a blown head gasket.

Fortunately, you can perform a leak down test to pressurize the combustion chamber with compressed air and measure the amount of air that leaks from the gasket.

How to Identify Signs of a Blown Gasket in a New Vehicle

head gasket new

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Modern vehicles have different coolant passages in their cylinder heads, something that allows heat from the engine to pass with each mile. The gasket prevents the coolant from flowing through the passages into the combustion chamber.

However, if you have a blown gasket, you may notice that the engine overheats and gets flooded with coolant. Also, the coolant could be consumed with exhaust gases if you have a leaky gasket.

You can tell if you have a blown gasket if you notice bubble formation in the coolant reservoir and you notice that there’s a lot of steam from the exhaust pipe.

Common FAQs on Blown Gaskets

gasket upper view

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Here are some common questions about blown gaskets.

What is the Work of a Gasket?

The gasket prevents the engine oil and coolant from leaking into the cylinders. Also, it seals the cylinders to ensure maximum compression.

What Causes a Blown Gasket?

The gasket can blow because of overheating. All engine parts are metallic and thus means the body expands when the temperature heats beyond a certain point, blowing the gasket. Abnormal combustion can also lead to detonation or pre-ignition problems of an engine. The burning strains the gasket and the valves that seal the combustion chambers.

How Can I know if I have a Gasket failure?

Some of the common signs of a gasket failure are the loss of coolant, a blown out radiator, rising temperature gauge, coolant in your oil, and white smoke from the tailpipe.

Can a Leak Happen During Warm-up?

Yes, a change in temperature range can cause a leak. For example, if the cylinder leakage happens when the engine is cold, the combustion gases will accumulate under the engine thermostat, pushing the coolant back through the radiator.

The result is an overflow condition at the reservoir. However, if a leak occurs when the engine is hot, the coolant becomes aerated with combustion gas, leading to a reduction in the cooling system efficiency.

Can I Drive With a Blown Gasket?

While it’s difficult to tell how far you can drive with a blown gasket, specific signs can show the severity of the problem. Sometimes the engine may not overheat, but you may have to part with hundreds of dollars for a new engine if you expose it to high-pressure conditions. You need to have the vehicle tested to determine if you can still drive.

How Much Does it Cost to Repair a Blown Gasket?

Replacing a gasket can be expensive due to its placement in modern engines. Some factors that could affect the cost include the block damage, number of cylinder banks, and other components that may need a replacement.

Fortunately, if you have moderate symptoms, the mechanic can use low-cost options like stop leak products to suppress the problem.

What Visual Signs Indicate a Blown Gasket?

Some of the visual signs that indicate a blown gasket is like white exhaust, milky oil, and bubble formations along the cooling system.

How Can I Minimize Gasket Problems?

You can reduce the chances of gasket failure by refilling the reservoir before the coolant drops below a pH of 7. Utilize water mixtures and readymade coolants, avoid adding the two at different times. Always cut the engine the moment it overheats.

Don’t forget to check and remedy any sign of overhearing. Have a professional mechanic diagnose the cause of overheating before it gets worse.

What Should I do to Ensure Gasket Problems Don’t Recur?

You need to ensure that what causes the first gasket failure is identified and corrected. Also, check the cooling system to see if it holds pressure and functions correctly. Make sure that the engine doesn’t ping or knock under load and always use the premium grade of gas.

You can also flush the cooling system including the hoses, radiator, and the heater core.

Why are Some Vehicles Prone to Gasket Failure?

You’ll realize that sealing problems are common in bi-metallic engines as the aluminum cylinder heads expand more than cast-iron cylinder blocks. The expansion rates also differ as the cylinder head heats up quicker than a cylinder block.

With this difference in expansion rates, it leads to a scrubbing effect t which wears out the stainless steel ring which keeps the combustion gases away from the cooling system. Modern cars now feature gaskets made of space-age materials that are resistant to scuffing.

Final Thoughts

The gasket plays a critical role in how your car’s engine work. A blown gasket not only causes severe damage, but it also could lead to major repairs that are expensive. I hope that the above tips should help you identify signs of a broken gasket before it’s too late.