Signs of A Blown Head Gasket And Tips to Prevent It

blown head gasket

Your car's head gasket is an essential component in your engine. It is located below the bonnet to seal between the cylinder head and the engine block. Head gasket failure is rare, but when it does occur, you are required to take immediate action.

More often than not, it may be challenging to identify a faulty head gasket. This is because the signs of head gasket failure are not obvious. In addition, being familiar with the working of a gasket can help you diagnose a faulty one. Therefore, this article will focus on the signs of a blown head gasket to help you quickly recognize a bad gasket.

If you suspect a faulty head gasket, keep reading to learn how to deal with this car emergency.

What Is A Blown Head Gasket?

The head gasket is installed between the cylinder head and engine block to seal the connection between the two parts. The primary function is to seal the oil return passage, coolant passage, pistons and cylinders.

A blown head gasket occurs when the engine overheats and expands at a different rate than the head. The thermal pressure creates a gap where the gasket fails to seal, resulting in a head gasket failure.

When a head gasket fails, the adhesive between the cylinder head and the engine block is broken. The result is coolant leaks, gases, or oil leaks escaping from the combustion chamber. Therefore, identifying a failed head gasket early helps to prevent further damages to your engine.

What Are the Classic Signs of A Blown Head Gasket?

Recognizing a blown head gasket is not straightforward since the signs are similar to other engine problems, like overheating. However, there are a few sure signs that can help you identify what you are dealing with.

Below are classic blown head gasket symptoms you should be on the lookout for.

1. Engine Overheating

The main reason why head gasket failure occurs is because of an overheating engine. For example, a coolant leak, faulty fan, or a clogged radiator causes an engine to overheat. When this happens severally, you get a bad head gasket.

Similarly, a blown gasket prompts the engine to overheat. Again, this is because the hot combustion gases leak into the cooling system, or the coolant leaks into the cylinders, burning it as steam.

One way to identify an overheating engine is to look for bubbles in the radiator. However, this depends on the severity of the leaking head gasket.

2. Oil Contamination

Oil contamination is another classic sign of blown head gaskets. A head gasket leak allows the antifreeze or coolant to leak into the oil return passages. When this happens, there is oil-coolant contamination.

When the coolant contaminates the oil, you will see a frothy milkshake-like consistency under your oil cap. In addition, when the oil contaminates the coolant, you can expect to find a film on the radiator cap that looks like mayonnaise.

3. White Smoke

A blown head gasket often results in thick white clouds of sweet-smelling smoke coming out from the exhaust. This is a sign that the coolant and engine oil are being burned up into steam in the combustion chamber after a gasket leak.

In addition to white smoke, you may notice blue smoke also coming from the exhaust. This indicates that the engine oil is leaking from an oil passage and into the cylinder. However, blue smoke is not always an indicator for head gasket failures since it could be from a damaged PVC system, a leaking valve seal, or worn rings.

4. Loss of Power

Loss of engine power occurs when head gaskets fail so that compressed air escapes, reducing the cylinder's pressure. When this happens, the pressure needed to move the pistons reduces, so you will have a rough running engine as the motor struggles to keep running.

5. External Leaks

Coolant leaks or external oil leaks between the engine block and the cylinder head gasket is textbook for a cracked block or a failed and leaking head gasket. In addition, external leaks symbolize a minor case of a blown gasket. However, ignoring this sign could further your engine issues or even result in fire.

What Are the Dangers of Ignoring A Blown Head Gasket?

If you suspect that your car has a blown head gasket, it is best to look into the signs above. Depending on the severity, you may be looking at a complete head gasket replacement. However, in the case of minor leaks, head gasket repair could be carried out using sealants.

Continuing to use your vehicle and ignoring a blown head gasket repair could have dire effects. Such include:

  • Ruined engine when the engine coolant happens to leak into the oil
  • The catalytic converter could suffer damages
  • Complete damage to the cooling system
  • Total radiator fail
  • Erosion of the hoses

How To Prevent A Blown Head Gasket

Preventing head gasket failures saves you a lot of money that could have been used for head gasket replacement or, worse, a new car. Acquiring a new head gasket is not expensive. However, the associated labor costs raise this fee since the gasket is located at the engine's center.

A few tips to prevent this are:

  1. Stick to the recommended car servicing schedule depending on the manufacturer and the car model. This helps to ensure that different parts are working as they should.
  2. Get a professional mechanic to check your car if you suspect a leaking head gasket. The mechanic will know how to diagnose the problem and offer you a solution. In addition, avoid driving your car in this situation as it could exacerbate a minor leak into a costly replacement.


A blown head gasket is a nightmare to a car owner because of the costs associated with repair or replacement. However, avoiding this process is more expensive and could mean getting a new car. We hope that this article will help you identify a failing head gasket, along with a few preventative measures to keep your car in check.

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