Your head gasket is incredibly important in the function of your engine. If it breaks your coolant and oil will leak and mix, which can cause disastrous consequences. If you notice any white smoke, overheating, loss of engine power, cloudy oil, or knocking sounds coming from the engine, book in to see your local mechanic who will be able to determine if you need to have your head gasket replaced or repaired.


What Is a Head Gasket?

Your car’s head gasket sits between the cylinder head and the engine block, and its primary function is to prevent fluids such as coolant and oil from coming into contact with one another.

It seals off the internal combustion chambers, which allows the head gasket to help the fuel ignition process run smoothly.


How Does A Head Gasket Work?

Your engine is split into two parts, the engine block and the cylinder head. The head gasket seals off these two areas, so that the fluids don’t mix, and continue to work as they should.

A head gasket works due to how it is made: it is usually made from three layers of steel pressed together, with a layer of rubber around the outside which adheres to the engine. As the engine gets warmer, the steel expands, and the seal is tightened, ensuring there is no way for the fluids to leak.


Why Is A Head Gasket So Important?

Inside the engine block are pistons and connecting rods that transform the force of expanding gases into mechanical power. The cylinder head contains the valves and spark plugs, which are responsible for delivering the spark that ignites the mixture of air and fuel in the combustion chamber.

Your head gasket needs to seal the gaps to stop leaks as the mixing of fluids from inside the engine. If these fluids mix, you could find yourself with engine failure. This is why it is important to have it looked at if you believe you have a leak.


How To Tell If You Have A Head Gasket Leak

Loss Of Power

If you have a head gasket leak, you could find yourself with a loss of power. If the leaking coolant gets clogged in the smaller orifices of the engine, the flow of oil will be interrupted, and it will affect the proper rate of combustion inside the engine. As the pressure in your engine has decreased, so will your engine power.

You may notice this first as it’ll be impossible to miss while driving. This is a sure sign you need to have a mechanic have a look at your head gasket.



If your head gasket is leaking, your engine will begin to overheat, as it no longer has a sufficient amount of coolant to keep the engine at the optimal temperature. You’ll be able to tell if your engine is overheating if you notice your temperature gauge needle is in the red, if you can smell burning, or if you notice steam coming from the engine, where the fluids are so hot that they begin to evaporate.


Engine Codes

If you see an engine code of p0300, it means that you could have an issue with your head gasket. This code also shows if you have a malfunctioning ignition or internal engine failure, so make sure to have your car looked at by a mechanic who can properly diagnose the problem.


Discoloured Oil

Since you should be checking your oil regularly, noting a discolour in your engine oil could point to a leaking head gasket.

This is where the coolant has mixed with the oil through the oil passages. The oil will look cloudy or milky, rather than its usual colour.


White Coloured Smoke

You should look into a head gasket replacement straight away if you notice white-coloured smoke. The white colour comes from the coolant being burned on the cylinders.

Alongside the smoke, you may notice what some people describe to be a ‘sweet’ smell. This is unique to the head gasket, as it occurs when the oil and the coolant mix together.


Knocking Sounds From The Engine

If you can hear a knocking that sounds like it is coming from inside the engine, it could be a sign that your coolant has leaked into the engine and has been taken in with the oil. Don’t ignore this noise – it could result in engine seizures.


Bubbling Coolant

If you look into the coolant reserve and see that the liquid is bubbling, it is likely that the coolant is at an unstable temperature due to a malfunction or rupture in your head gasket. This should be looked at as soon as possible to avoid further complications and potential engine failure.


What Should I Do If I Think My Head Gasket Has A Leak?

If you have noticed any of these symptoms, you should get a professional mechanic to take a look at your head gasket as soon as possible. Driving with a blown head gasket can be very dangerous – your engine will no longer be able to regulate its temperature, so it will be extremely hot and has the potential to fail on you whilst driving, which could be a disaster.

Use BookMyGarage to find the best deal on your head gasket repair by comparing garages in your local area. You can sort by price, distance, ratings, and availability so you can choose the garage that suits your needs best.


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General Repair


What Is Head Gasket Sealer?

Head gasket sealer is a substance that is poured into your radiator. As the car runs and the temperature rises, it begins to fill any small cracks or tears in your head gasket, hardening and preventing leaks.

Even though the sealer will fill in any gaps or cracks, it is recommended that the head gasket sealer is only used as a temporary fix – you should have a mechanic take a look at your gasket if you believe it needs replacing. It can be costly, but if you leave it until something else goes wrong, you could end up spending much more than necessary.


What To Know About Your Head Gasket Repair

Your head gasket repair is not a straightforward job – since it is located in the centre of the engine block, the mechanic will need to remove certain elements of your engine to gain access to it. Because of this, the repair could take as long as 5 hours to a whole day to complete. Because of this, we recommend you don’t try to fix the head gasket yourself.

It can also cost anywhere from £400 to £1500 to repair, based on the garage, and the make and model of your car. However, if you leave your leaking head gasket to worsen over time, you could find yourself spending much more money in the long run, as you could end up with warped cylinder heads, or worse, irreversible damage which may render your car a write-off.

Luckily, most head gaskets will last as many as 200,000 miles – they are built to last and withstand those sweltering temperatures. Because of this, there are a few things you can do to ensure the lifespan of your head gasket:

  • Ensure that you are taking your car to be serviced every twelve months at a minimum.
  • Regularly inspect your engine for any warning signs.
  • Remember to top up your coolant and oil levels when required.
  • Stop driving if you think you might have a problem with your engine – don’t inflate your maintenance costs any more than they need to be.