Blown Head Gasket: How Much Does It Cost to Replace?
The cost to replace a head gasket in the UK is between £284 and £2,946 with an average of £585. It’s one of the most expensive replacements and the most interesting one as well. The seal for the head gasket costs less than £100 in most cases. However, it is a labour-intensive replacement. So, the majority of the cost goes into labour as it may take up to 8 hours to replace a blown head gasket.
The cost of fixing a head gasket is highly variable. It mainly depends on the make of your car and the type of repair shop you’re visiting. Read on as we discuss the detailed breakdown of the cost to replace a blown head gasket, along with its signs and causes.
What is a Head Gasket?
A head gasket is a critical component in an internal combustion engine that serves as a seal between the engine block and cylinder head. It is made of multiple layers of steel with elastomer coatings. A head gasket’s primary functions are to:
- Seal the combustion chambers to maintain compression and prevent combustion gases from escaping.
- Keep engine oil and coolant separate, preventing them from leaking into the cylinders or mixing with each other.
What Causes a Head Gasket to Blow?
Overheating is the main cause of blown head gaskets. It can warp the cylinder head and damage the gasket’s seal. This happens when there’s low coolant, a faulty thermostat, a failing water pump, or a clogged radiator. Age and wear also play a role, as head gaskets naturally degrade over time due to constant temperature fluctuations and exposure to combustion gases.
Some engines with poor design are more prone to this problem, where abnormal combustion, like pre-ignition or detonation, creates extra pressure. Then there’s the improper installation. Over or under-torquing of cylinder head bolts can also cause the head gasket to blow.
7 Signs of a Blown Head Gasket
Here are the 7 most common signs of a blown head gasket.
1. Engine Temperature Gauge Turn Red
One of the most common and obvious signs of a blown head gasket is frequent engine overheating. If you notice your temperature gauge climbing into the red zone or steam coming from under the bonnet, it’s time to pull over immediately and have your vehicle inspected for a blown gasket.
2. Coolant Loss with No Visible Leaks
If you find yourself constantly topping up the coolant but can’t see any external leaks, it could be escaping into the combustion chambers through a blown head gasket.
3. White Exhaust Smoke
Another noticeable sign of a blown head gasket is white smoke coming from the exhaust. This occurs when coolant leaks into the combustion chamber and mixes with the fuel, creating a visible white vapour.
4. Milky Engine Oil
If you check your oil and notice it has a milky appearance, this is a clear sign that coolant is mixing with the oil. This mixture can be found on the underside of the oil filler cap or the dipstick.
5. Rough Idle, Misfires, and Power Lag
When a head gasket blows, you might experience a rough idle, engine misfires, or a noticeably uneven running engine. You also might notice your car struggling to accelerate or maintain speed, especially on inclines. This occurs because the damaged gasket allows compression to escape from the cylinders, not allowing the engine to generate enough power.
6. Sweet Smell from Engine Bay
A sweet, syrupy smell coming from the engine bay indicates coolant leaking from somewhere. While this could be due to various issues, a blown head gasket is one of the most common culprits.
7. Coolant or Engine Oil Leaks
A blown head gasket might cause visible engine oil or coolant leaks where the cylinder head meets the engine block. These leaks might be small at first but can worsen over time.
4 Factors Affecting Head Gasket Replacement Costs
Head gasket replacement cost is affected by many factors, including:
1. Car’s Make and Model
Different cars have varying engine designs and accessibility, which impacts labour time and complexity. Some engines, like those with overhead cams or complex timing systems, require more labour to access the head gasket. Similarly, for some vehicles, you may need specialised tools. Here is the head gasket replacement cost for various brands in the UK:
| Make | Head Gasket Replacement Cost UK |
| Volkswagen head gasket replacement cost | £284 to £1,667 |
| Ford head gasket replacement cost | £346 to £1,182 |
| Audi head gasket replacement cost | £394 to £2946 |
| BMW head gasket replacement cost | £565 to £2,309 |
| Toyota head gasket replacement cost | £372 to £1,345 |
| Kia head gasket replacement cost | £309 to £1,197 |
| Vauxhall head gasket replacement cost | £375 to £1,238 |
| Mercedes-Benz head gasket replacement cost | £483 to £1,533 |
| Land Rover gasket replacement cost | £407 to £1,598 |
2. Type of Repair Shop
Another factor affecting the replacement cost of a damaged gasket is the type of repair shop you choose. The cost of labour varies depending on your location, the mechanic’s experience, and the shop’s overhead costs. You must consider that while well-established shops with experienced mechanics may charge more, they often provide higher-quality work.
3. Extent of Damage
If the head gasket failure has caused additional engine damage, repair costs will increase. Often, mechanics recommend replacing related components like timing belts or water pumps while the engine is disassembled. This is done to cure the root cause, which allowed the head gasket to blow in the first place. Similarly, if the cylinder head is warped, it may also need machining or resurfacing, increasing the cost of replacement.
4. Quality of Parts
The type of gasket and other things like fluids and engine oil (you have to change these when the gasket is replaced) you choose can also affect the cost of replacement. OEM (Original Equipment Manufacturer) parts are usually more expensive than locally-made alternatives. Therefore, if you choose a higher quality gasket, it may add an extra £50 to £100 to the total replacement costs.
Frequently Asked Questions
1. Is it safe to drive with a blown head gasket?
Driving with a blown head gasket is technically possible but highly inadvisable due to the potential for severe engine damage. A blown head gasket can cause coolant to leak into the engine, increasing the risk of overheating. Also, if motor oil mixes with coolant, it loses its lubricating properties, leading to irreparable engine damage. So, no, while you can, it’s not safe to drive with a blown head gasket.
2. Is the head gasket a DIY replacement?
No, replacing a head gasket is not a DIY project unless you are an expert mechanic and have access to special tools. The head gasket is located between the engine block and the cylinder head, and replacing it involves disassembling significant parts of the engine, including the timing components and various other engine systems. Additionally, the surfaces of the engine block and cylinder head must be machined, which is not feasible for a DIY mechanic. So, unless you have extensive automotive repair experience, you shouldn’t do it.
3. How long does a head gasket last?
While there’s no set lifespan, a well-maintained engine should see its original head gasket last 150,000-200,000 miles in most cases. However, some vehicles may experience failures earlier, while others can go well beyond 200,000 miles without issues.
Wrapping Up: How Much Does It Cost to Replace a Blown Head Gasket?
In conclusion, replacing a blown head gasket is a huge expense that can be both costly and time-consuming. It’s essential to be vigilant in monitoring your vehicle for signs of a potential issue.
By regularly checking coolant levels, addressing overheating problems promptly, and following recommended maintenance schedules, you can help prevent head gasket failure.
Regular vehicle maintenance is not just about saving money; it’s also about ensuring your safety and the longevity of your vehicle. It can also help you while selling your car.
