Head Gasket Repair & Replacement

A tightly fitting cylinder head gasket is essential to the wellbeing of your engine. The function of the gasket is to ensure a good seal between the cylinder head and the engine block, and to prevent the escape of the various fluids and gases that are an integral part of any internal combustion engine. A blown or leaking cylinder head gasket needs immediate attention in order to prevent damage to other parts of your engine, so if you have a problem, you can call on us. AutoMend is one of the UK’s leading automotive repair and maintenance networks, and our members are available all across Wales, Ireland, Scotland and England, so they are never far away. We have a quick and simple online search and quotation system that will get you in touch with trusted industry experts who can organise your cylinder head gasket repair quickly and at the right price.

How can I tell I have a head gasket problem?

Your vehicle engine usually needs three different sets of liquids in order to operate, and each set has its own individual route around the engine. The sets in simple terms are:

  • Lubrication – motor oil
  • Fuel – petrol or diesel
  • Coolant – usually a water and glycol (antifreeze) mixture

Seals are used in various places around the engine in order to prevent each of these sets of liquids coming in contact with each other. The most critical of these seals is the cylinder head gasket, which has multiple functions. It seals the cylinders themselves, to maintain compression, plus it seals off the oil and water conduits which sit between the cylinder head and the engine block. If a seal fails, water or oil may be allowed to get where they shouldn’t, and a number of issues will become apparent. It is important to be able to recognise the signs of gasket failure, as severe engine damage can occur if a faulty gasket is not replaced at once.

Recognising head gasket problems

Exhaust Smoke

Blue exhaust smoke may indicate that you are burning oil as a result of a leaky gasket. White smoke (steam) could be coolant getting into the cylinders, which risks damaging your catalytic converter. When a head gasket blows, a puff of steam from the exhaust may be the only indicator that something is wrong, and if you miss it, you may continue to drive as the car will feel normal, until the coolant has all been lost. Once that happens, the engine may seize up due to overheating.

Compression Loss

Loss of acceleration or a roughly-running engine can be an indicator of head gasket problems.


This is a killer for a modern engine, and has many causes related to your head gasket. As well as loss of coolant, another source of overheating (and consequent engine wear) is water and antifreeze being allowed to mix with the motor oil. In addition, a leaking gasket can allow air to get between it and the head or the block, causing air pockets in the cooling system. If these pockets get trapped in the coolant thermostat, it could malfunction and stay closed when it should be open, leading to further temperature increases.

Some frequently asked questions

What is a head gasket for?

The purpose of the head gasket is to act as a seal between the cylinder head and the engine block. The seal needs to be tight in order to ensure maximum compression, and also to avoid engine oil or coolant being able to leak into the cylinders. Of all the seals on your vehicle, the cylinder head gasket is the most critical. The gasket itself has to withstand enormous pressure, and if a leak occurs, the fluids released can cause damage to your catalytic converter, or even major engine damage.

What is a head gasket made from?

Early head gaskets were made from composite materials including graphite and even asbestos. This type of gasket was more fragile than later gaskets, and prone to blow outs. In addition, the presence of asbestos has been a health concern for many years. Older vehicles may still have this type of gasket, which is one more reason for getting an expert to do any head gasket repairs rather than trying to do it yourself.

MLS or multi-layered steel gaskets are most commonly in use today. An MLS gasket is usually made up of between 2 and 5 layers of thin steel, with a resilient elastomer layer in between the steel layers. On the outer surface, where the gasket contacts the engine block and cylinder head, there is usually a coating layer of a flexible rubbery substance, which helps the gasket to adhere to both metal surfaces.

Copper gaskets made from a solid copper sheet are highly durable but have traditionally required machining work to be carried out on the cylinder before fitting, making them expensive. The machining work entails the removal of the engine block from the vehicle, and the process which is called 'O-ringing' fits a wire border around the top of each cylinder. The wire contacts and bites into the copper sheet, giving an excellent seal. However, companies have recently hit upon the idea of producing copper gaskets pre-fitted with sealing wires within the gasket itself. This innovation enables retrofitting into the engine block without the need to remove it, and it does away with the need for machining.

Can I repair or tighten a head gasket myself?

If you are keen to be a home mechanic, it may seem that a head gasket repair is a simple place to start. Prices for professional repairs can appear quite high, and the head gasket itself is a relatively cheap part to buy. However, it is not recommended to try to do the job yourself.

The reason that professional head gasket repairs seem expensive is that they are tricky to do, and therefore take a lot of time. Roughly 75% of the cost of this type of repair is usually made up of labour costs. Removing and then replacing the cylinder head takes most of the time, followed by removing any remnants of the old gasket. In addition, the surfaces of the block or the head may have been cracked or damaged, and machining may be necessary in order to achieve a good seal with the new gasket.

There are products on the market that can be used to seal a leaking cylinder head gasket at home. However, the chemicals involved are harsh and need careful handling, and you cannot be sure of achieving a 100% seal. If you use these products at all, they should be considered a temporary measure and nothing more.

The cylinder head gasket is the most crucial seal on your vehicle, and if it’s not fitted correctly, you risk damaging your engine. It’s much safer and will be cheaper in the long-run to leave it to a member of our extensive network of AutoMend repair professionals.

What will AutoMend do for me?

Our UK-wide network consists of a series of car and van garages plus mobile mechanics - more than 9000 of them, each with their own individual specialities and skills. What they all have in common is their dedication to providing the best possible customer service, and expert vehicle repair, maintenance and testing services, at the right price.

Getting a quote for a cylinder head gasket repair or head gasket replacement couldn’t be easier. Our website puts you directly in contact with all the garages and mechanics in your region. Tell us your post code and location, and we will show you the business names and phone numbers of all our local network members, plus how far from you they are located. You then have the option of asking for an online quote, or simply calling the garage to discuss your needs.

AutoMend is great for busy people who don’t have the time to search through multiple websites or to ring up all the local garages for quotes. Ask for multiple online quotes from our members, and then sit back and compare the prices, it’s so easy. Quotes are free, and you are under no obligation to accept any of them, but we’re confident that you’ll be delighted with the deals our trusted, industry-approved network members can offer you.