If your head gasket is blown, or if you think it's about to fail, our guide will help you understand the costs of fixing it. We’ll also explain a little bit about what the head gasket does, and how to prevent issues in the future.  

What is a head gasket? 

An engine or cylinder head contains the explosive power of an internal combustion engine. It is bolted to the top of the cylinder block and contains various key components that allow an engine to run.  

Because the cylinders experience very high levels of pressure, the sealing face between the cylinder head and block needs a gasket. 

This gasket, therefore, needs to cope with extremes of heat, pressure, and moisture, as there are water and oil routes that also pass through it. There are various points of failure, all of which are not good for an engine’s performance.

How much does a head gasket repair cost?  

Full-head gasket repair in the UK can cost between £550 and £1,700.  

How much strictly depends on the region, type of car, and whether or not the engine has overheated. So, we can’t give you a personalised figure.  

A vehicle with an engine in any kind of ‘V’ arrangement, i.e. a V6 or V8, can cost considerably more, as they have two cylinder heads and, therefore, two gaskets. In many cases, removing the heads is often easier with the engine out.   

Why is a new head gasket so expensive?  

Gasket repair costs a lot due to the expertise needed to repair it. 

As with many things on cars, it's not the cost of parts that drives up the repair price. It's the labour time. A new head gasket will usually cost around £20, but getting to it involves stripping the engine to its essential parts.  

This was bad enough back in the days of simple cars, but now, with cars having all manner of complex ancillary components and requiring special tools or procedures for many things, the cost can soon become eye-watering.  

Gasket repairs can be unpleasant for your finances. Split the cost of repairs into interest-free monthly repayments with a reliable partner from Bumper Car Repair Finance. 

Head gasket repair cost for different car brands 

Head gasket repair costs often depend on your car type. While we can’t give you a specific quote, we do have approximate costs for different care manufacturers.  

Here’s what UK drivers can expect to pay for a head gasket replacement for the following Car Manufacturers: 

• Nissan - £400 to £1,000 
• Toyota - £400 to £1,000 
• Vauxhall - £500 to £1,200
• Ford - £500 to £1,200 
• Honda - £600 to £1,300 
• Volkswagen - £600 to £1,300
• BMW - £800 to £1,500
• Audi - £800 to £1,500 
• Mercedes-Benz - £1,000 to £2,000 
• Land Rover - £1,200 to £2,500 

Breakdown of head gasket repair steps 

An experienced mechanic is necessary if your head gasket has blown, and you shouldn’t try to repair it yourself. Here are the main steps mechanics will take when repairing your car. 

• Inspection — Your mechanic will investigate your blown gasket, paying special attention to the cylinder head. 
• Replacement — The gasket will be replaced where needed. Other parts of the car may have been damaged, and these will also need repairs. 
• Sealing — If the cylinder head is damaged, your mechanic may skim it to ensure the correct amount of connection. 
• Connection — Your mechanic may also replace the cylinder head bolts. This isn’t always necessary. 
• Completion — Once the new gasket is installed, your mechanic will complete a full inspection to ensure that there are no other problems. This is just to guarantee your car is running safely. 

These steps can’t be carried out by amateur car enthusiasts, and the car needs to be carefully taken apart to reach the gasket. The complexities make a blown gasket more expensive than other car repairs. 

Are there any additional costs? 

There may be additional blown head gasket costs if your car has mechanic complications.  

These costs can be caused by: 

• Engine inspection fees 
• Replacing broken components (e.g. water pump or thermostat) 
• Coolant and oil flushes 

To get an accurate quote, make sure your mechanic provides a very thorough examination. This way, you’ll know if there are any complications before the repairs begin. 

What are the signs of a blown head gasket?  

Some serious engine issues can irreparably damage your car if you continue driving, so it’s important to know the signs of a blown head gasket to be able to identify if it has happened to your car.  

Here are 5 signs you should know: 

1. Reduction in engine power 

When a head gasket breaks, the seal is broken on one or more cylinders; this means the energy from the combusting fuel will dissipate instead of providing power for propulsion.  

Depending on where the gasket has breached can affect how much power is lost, but typically, a 4-cylinder car will be significantly down on power with a minor head gasket leak.  

2. Smoke from under the bonnet  

One of the things a head gasket does is seal the waterways between the cylinder head and block. If the gasket breaks at one of these locations, water from your car's coolant system will exit the engine.  

This water and coolant mixture will likely eject as steam due to the extremely high temperature and pressure the coolant is under. 

3. Milky-coloured oil  

Because the head gasket seals oil and coolant routes between the head and cylinder block, coolant can mix with the car's engine oil when it breaks.  

Due to the high heat and mixing action the oil experiences in everyday use, the water/coolant and oil mixture emulsifies, creating a white-coloured foam. This foam will typically be present at the oil filler cap and when draining the oil.  

4. Smoke from the exhaust  

A common symptom of a failed head gasket is steam from the exhaust. This is due to coolant getting into the combustion chamber. The coolant is evaporated into steam and forced out of the exhaust.   

Because the coolant system operates at a moderately high pressure, it will continue to be forced into the cylinders until it is all gone. 

5. Overheating  

When the coolant is escaping, either into the engine or out into the engine bay, it will eventually run dry. At this point, it no longer removes heat from the engine via the radiator, and the engine will begin to overheat.    

Can I drive my car with a blown head gasket?  

There is no definitive answer because there are a few different ways a head gasket can break. In any case, you should not drive the car more than is necessary.  

If the car is overheating or losing significant amounts of coolant, it can be very dangerous for the engine to continue running. As the coolant is depleted, the engine will become incredibly hot.  

What will happen if I drive my car with a blown head gasket?  

The engine will likely overheat, and if driven for an extended period - this could be as little as 5 minutes if severe coolant loss occurs - then the cylinder head can warp.  

This will increase the cost of repairing your head gasket by at least twice, as the head must now be machined.   

In some extreme cases, the engine block can crack, requiring an entire engine replacement.  

What causes a head gasket to fail?  

Generally, head gaskets fail due to excess heat within the engine. A lack of coolant or improper engine care can cause this. Learn more about each factor below. 

Overheating  

When an engine runs without coolant, the block and cylinder head will heat up rapidly, past the temperature at which they are supposed to operate.   

This overheating can cause warping of the components, particularly the head. When this happens, gaps can be created where the head is no longer flat, allowing the high-pressure gases to force a path through the gasket.  

Not allowing your engine to warm up  

When starting a cold engine, it is crucial to not over-rev until the car is up to operating temperature.   

Excessively revving a cold engine can cause concentrations of high heat, whilst other parts of the engine are still relatively cold. This causes warpage and even cracking in the extreme.   

You shouldn’t allow the engine’s rpm to exceed 3,000 until the car is at operating temperature. This is usually a mile or two for petrol cars, whereas diesel engines can take twice as long.   

Improper engine timing  

An engine's combustion cycle is designed for maximum power generation whilst maintaining longevity. Certain faults with ignition and timing systems can cause this cycle to be slightly out of time.      

One common cause is a stretched or skipped cambelt. This can cause the valves in the engine to remain closed at the time they should be open, creating a pre-ignition problem. 

This causes a spike in pressure in the engine the gasket was not designed for, driving a gasket to fail and allowing pressure to escape. 

Is it a big job to replace a head gasket? 

The head gasket separates the two main components in an engine, the block and the cylinder head; therefore, it takes a lot of time to complete a replacement. 

The steps involved differ from car to car; as mentioned, cars with engines in a ‘V’ configuration are much more time-intensive to repair. 

In a typical inline-engined car, a mechanic would remove all components attached to the cylinder head, which includes the intake and exhaust manifold, the turbo if fitted, the water pump, the cambelt or chain and tensioner and any other smaller components. 

Depending on the engine design, the head can then be removed, either with or without the camshafts. Once the head gasket has been removed, the faces cleaned, and the new gasket installed, the various components can be reassembled. 

Does a blown head gasket mean I need a new engine? 

This depends on the severity of the problem and what caused the gasket to fail. If, as mentioned above, the head gasket failure was caused by the engine overheating, then the cylinder head and block must be examined. 

If an engine has been severely overheated, the head will often be too warped to reuse. In some cases, the engine block, the central part of the engine, can crack or warp. In many cases, this will mean that these parts will need to be replaced. 

How long should a head gasket last? 

In many cases, if the car has been looked after, the head gasket should last for at least 100,000 miles.  

Some exceptions exist, where manufacturers improperly specify the gasket materials. Still, more often than not, a head gasket will never need to be replaced if the car is maintained and cared for properly. 

Head gasket repair - Final thoughts 

If you have a blown head gasket, you can end up with significant damage and even complete engine failure. Getting the gasket fixed as soon as possible is critical. So, hopefully, this article has pointed you in the right direction.   

Split the cost of a head gasket replacement and other repairs with Bumper. Pay your bill in monthly instalments at no extra cost and choose from 1000s of dependable repairers.