How much does a head gasket repair cost in the UK?

Head gasket repair cost by car type

Prices below include head removal, a new gasket, head skimming at an engineering shop, new head bolts, coolant refill, and pressure test. Always confirm these are included in any quote.

Prices are approximate and vary by engine complexity, whether additional repairs are needed, and garage rates. Always get a written quote before work starts.

Signs of a blown head gasket

Get the car inspected immediately if you notice any of the following. Continuing to drive with a suspected head gasket failure can quickly escalate to a total engine loss.

• ⚠White or sweet-smelling smoke from the exhaust (especially on a warm engine)
• ⚠Coolant level dropping without any obvious external leak
• ⚠Mayonnaise or brown sludge under the oil filler cap or on the dipstick
• ⚠Oil contamination in the coolant reservoir (milky, cloudy coolant)
• ⚠Engine overheating or temperature gauge rising quickly
• ⚠Bubbles in the coolant expansion tank when the engine is running
• ⚠Rough running, misfires, or loss of power across one or more cylinders
• ⚠Sweet smell inside the car or from the heater vents

What affects the price?

Engine complexity and access

A simple 4-cylinder engine in a small hatchback is far quicker to strip than a twin-cam unit in a premium car or a V6/V8 in a larger vehicle, which may have two cylinder heads. Labour hours vary from 8 hours to 20+ hours depending on the engine.

Whether the head needs skimming

Most heads require machining flat (skimming) after a head gasket failure, because overheating typically warps the surface. Skimming adds £80 to £200 and usually requires the head to go to an engineering shop overnight. It is an essential step, not optional.

Whether the head is cracked

If the cylinder head is cracked (from severe overheating), a replacement head is needed rather than a repair, significantly increasing costs. A new or remanufactured head costs £150 to £600 for common engines, more for rare or premium units.

Timing belt or chain condition

Because the head must come off to replace the gasket, most garages recommend replacing the timing belt or inspecting the timing chain at the same time, since the components are already accessed. This adds parts cost but saves significant labour in the future.

Common questions about head gasket repairs

What is a head gasket and why does it fail?

The head gasket is a seal that sits between the engine block (the lower part containing the pistons) and the cylinder head (the upper part containing the valves). It seals the combustion chambers, oil passages, and coolant passages from each other. When it fails, these fluids can mix or leak externally, causing overheating, coolant loss, oil contamination, and in severe cases, engine damage. The most common cause of head gasket failure is overheating, which causes the metal components to expand and distort, compressing and eventually cracking the gasket.

What are the signs of a blown head gasket?

The most common signs are: white smoke from the exhaust (coolant burning in the combustion chamber); coolant loss without an obvious external leak; mayonnaise-like brown sludge under the oil filler cap or on the dipstick (coolant mixing with oil); overheating or the temperature gauge rising rapidly; bubbles in the coolant reservoir when the engine is running; a sweet smell from the exhaust; and oil in the coolant. Not all of these need to be present simultaneously. A pressure test, combustion gas test (Bloc Chek), or chemical coolant test can confirm a head gasket failure.

What does a head gasket repair include?

A head gasket repair includes: removing the cylinder head (which involves draining coolant, removing the intake and exhaust manifolds, valve cover, timing belt or chain, and all ancillary components connected to the head); replacing the gasket itself; having the cylinder head surface inspected and machined flat (skimmed) if it has warped; fitting new head bolts (most modern engines use torque-to-yield bolts that must not be reused); reassembling and refilling with fresh coolant; and a pressure test to confirm the repair holds. The machining (skimming) is often sent to a specialist engineering shop and adds cost and time.

Should the cylinder head be skimmed during a head gasket repair?

Almost always yes. When a head gasket fails due to overheating, the aluminium cylinder head typically warps slightly, creating an uneven mating surface. Fitting a new gasket to a warped head will cause the replacement gasket to fail quickly. Skimming (machining flat) the head surface is standard practice and costs £80 to £200 at an engineering shop, but it is an essential part of doing the job correctly. A quote that does not include skimming should be questioned.

Is head gasket sealer worth trying before a full repair?

Head gasket sealers (chemical additives poured into the coolant) are a short-term emergency measure, not a repair. They can sometimes slow a minor external coolant leak or a small internal breach long enough to get to a garage or make a low-value car drivable for a short period. They do not fix warped heads or seal oil-into-coolant contamination. Using a sealer on a significant failure can clog coolant passages and the heater matrix, potentially causing further damage. Treat sealer as a temporary option only, not a substitute for proper repair.

What happens if you drive with a blown head gasket?

Continuing to drive with a blown head gasket causes progressive damage. If coolant is entering the combustion chamber, the engine may hydrolock (water cannot compress, so a cylinder can seize), bending a connecting rod and destroying the engine. Coolant mixing with oil strips the oil of its lubricating properties, causing accelerated bearing and cylinder wall wear. Overheating causes warping of the head, the block deck, and eventually cracking of both. What starts as a £700 head gasket job can become a £3,000+ engine rebuild or replacement within days of continued driving.

Is it worth repairing a head gasket or should I replace the engine or car?

The decision depends on the car value versus repair cost and the wider condition of the engine. If the car is worth significantly more than the repair (say, £6,000 car with a £900 repair), proceed. If the engine has high mileage and the repair cost approaches the car value, a used or remanufactured engine replacement may be better value long-term, as the existing engine may have other wear issues. Get quotes for both options before deciding. A garage should be willing to do a full inspection first and advise honestly.

How long does a head gasket repair take?

A typical head gasket repair takes 1 to 3 days. This includes stripping the head, sending it for skimming (which usually takes an overnight trip to an engineering shop), and reassembling. Some very accessible engines (such as a Ford Fiesta 1.6) can be completed in a day by an experienced technician. Complex engines, twin-cam engines, or cars where the head is difficult to access can take 3 to 4 days. Always book the car in for the full expected duration and confirm with the garage.

Will a new head gasket come with a warranty?

Yes, most garages offer a parts and labour warranty on head gasket work, typically 12 months or 12,000 miles. This should cover the gasket failing again within that period from workmanship or parts defects. However, if the repair fails because the root cause of the original failure was not addressed (such as a cracked head that was not identified), the warranty may not cover that. Always ask the garage to confirm what checks they performed on the head and whether it was skimmed.