Cost of living increases are impacting many of us. With prices rising across the board, it’s often difficult to set money aside to cover those unforeseen expenses.
Yet, at the same time, our cars have become increasingly sophisticated, with all manner of high-tech features and advanced materials. As a result, replacement parts are much more expensive than they used to be, not to mention more complicated to install.
With this combination of pricey parts, increased labour costs, and reduced disposable income, it’s important to know which parts of your car are the most expensive to replace. This will make it easier to prioritise repairs and manage your maintenance schedule.
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Hybrid and electric car battery
Description and function: The battery stores electrical energy to partially power hybrid vehicles and fully power electric vehicles (EVs). Without a battery, an electrified car can’t run (even if it’s a hybrid which also has a combustion engine).
Why it’s expensive: The cost of replacement hybrid and electric batteries reflects their advanced technology and materials (e.g. rechargeable lithium-ion battery packs) - and the precise engineering required to create them.
Signs of trouble: There are a few telltale signs that your battery is failing, such as a reduced electric range, loss of acceleration power, slow charging, overheating – or seeing the battery warning light on your dashboard.
Maintenance tips: To keep your battery running as long as possible, charge it regularly, avoid extreme (hot or cold) temperatures, keep the software updated, and carefully follow the manufacturer’s maintenance guidelines.
Cost breakdown
- Average estimated cost range for parts: £1,100 to £5,500
- Average estimated cost range for labour: £330 to £880
Automatic gearbox
Description and function: The automatic gearbox shifts gears automatically while you’re driving based on the engine’s load and the car’s speed, so you can focus on steering and acceleration.
Why it's expensive: Automatic gearboxes are complex systems with multiple components including hydraulics and electronics, which means replacing them is a labour-intensive process.
Signs of trouble: If your gearbox needs replacing, you might find you’re slipping or having difficulty shifting gears, you might notice fluid leaks under your car – or see dashboard warning lights.
Maintenance tips: To extend the life of your automatic gearbox, regularly check your fluid levels (and change fluids when needed), keep up with your servicing schedule, don’t overload your car - and avoid aggressive driving.
Cost breakdown
- Average estimated cost range for parts: £1,100 to £3,300
- Average estimated cost range for labour: £330 to £660
Turbocharger
Description and function: The turbocharger is part of the engine. It consists of a turbine and a compressor, which work together to force compressed air into the engine to make it more efficient and powerful.
Why it's expensive: Due to their function and where they sit in the engine, turbochargers are made from durable materials that can withstand high temperatures and fast rotation. Precision engineering is also required for their installation.
Signs of trouble: If you notice your engine whining or losing power, your exhaust giving out blue or white smoke, or the ‘check engine’ light coming on, your turbocharger could need replacing.
Maintenance tips: Using high-quality synthetic oil and changing it regularly will help to maintain your turbocharger. You should also let your engine warm up before driving – and cool down before you switch it off. Finally, check for leaks and visible damage to hoses and connections on a regular basis.
Cost breakdown
- Average estimated cost range for parts: £440 to £1,650
- Average estimated cost range for labour: £220 to £440
Steering rack
Description and function: The steering rack connects the steering column to the wheels, so that when you turn the steering wheel, the car’s wheels respond correctly.
Why it's expensive: The steering rack is costly because it’s such a complex part with multiple precisely designed and machined components. Installation adds to the price because the steering rack needs to be properly integrated with the electronic power steering (EPS) system.
Signs of trouble: Look out for power steering fluid leaks under your car - and listen out for any strange noises when turning the steering wheel. You might also find the steering wheel is either too loose or too stiff.
Maintenance tips: To maximise the lifespan of your steering rack, regularly check the power steering fluid levels, look for leaks - and listen out for unusual sounds. You should also have your wheels aligned periodically.
Cost breakdown
- Average estimated cost range for parts: £440 to £1,100
- Average estimated cost range for labour: £220 to £440
Head gasket
Description and function: The head gasket sits between the engine block and the cylinder head, making a seal that stops coolant, oil, and combustion gases from escaping, as well as separating the coolant from the oil.
Why it's expensive: Head gasket replacement is a time-consuming process, so labour costs account for most of the cost. It involves taking a lot of the engine apart then putting it back together.
Signs of trouble: Red flags include your engine overheating or misfiring, seeing coolant leaks under your car or around the engine – and white smoke coming from your exhaust.
Maintenance tips: Keep an eye on your engine coolant level, perform regular flushes – and fix small leaks promptly to prevent major damage. You should also check your engine temperature on a regular basis.
Cost breakdown
- Average estimated cost range for parts: £330 to £880
- Average estimated cost range for labour: £330 to £550
Clutch
Description and function: The clutch connects the engine and the gearbox, allowing you to switch gears - and giving you control over the power to the wheels.
Why it's expensive: Your clutch is expensive to replace because to get to it, a mechanic has to take apart a lot of the drivetrain’s components and remove the gearbox. It also needs to be made from high-quality, durable materials to withstand wear and tear, which adds to the cost.
Signs of trouble: Slipping or grinding gears, a spongy or stiff clutch pedal, and difficulty shifting gears are dead giveaways that your clutch needs replacing. Other signs include reduced acceleration, vibrating pedals, and a burning smell.
Maintenance tips: You can make your clutch last longer by regularly checking the hydraulic fluid levels, keeping up with your servicing schedule, and avoiding riding the clutch.
Cost breakdown
- Average estimated cost range for parts: £330 to £900
- Average estimated cost range for labour: £330 to £550
Alternator
Description and function: The alternator converts energy from the engine into electrical power that recharges the battery and runs the electrical systems while you’re driving.
Why it's expensive: An alternator is a expensive to replace due to being a complex electromechanical component that needs precise engineering, and must be made from durable, high-quality materials to withstand heat and vibration. It’s also a labour-intensive part to install, which adds to the cost.
Signs of trouble: If your battery runs out often or fails to hold a charge, it could be down to your alternator. Other warning signs include the engine stalling, dim or flickering lights, battery warning lights on your dashboard - and whining or grinding sounds coming from the alternator.
Maintenance tips: Look after your alternator by keeping an eye on your battery and alternator output voltage, checking electrical connections, promptly replacing or fixing any loose, worn, or damaged parts - and making sure you have the correct drive belt tension.
Cost breakdown
- Average estimated cost range for parts: £380 to £870
- Average estimated cost range for labour: £110 to £495
Airbags
Description and function: An airbag is a critical car safety feature, designed to keep you safe in a crash by deploying and cushioning you from the impact.
Why it's expensive: Airbags are expensive because they’re part of a wider system that features sensors, electronic controls and mechanical components to help them work. They also need extensive testing and precision engineering, which adds to the cost.
Signs of trouble: If there’s a problem with your airbags, you’ll see the airbag warning light on your dashboard. You may also be able to see if there’s any physical damage to the airbags.
Maintenance tips: The best thing you can do to extend the life of your airbags and make sure they’re working properly is to run regular systems checks (including the warning light). Keep up with your scheduled services, and don’t make any modifications to your car that could affect the airbags.
Cost breakdown
- Average estimated cost range for parts: £220 to £1,100
- Average estimated cost range for labour: £110 to £220
Catalytic converter
Description and function: The catalytic converter reduces the emissions from your car, converting toxic pollutants into less harmful gases and substances before expelling them into the air from your exhaust.
Why it's expensive: Catalytic converters contain precious metals such as palladium, rhodium, and platinum, which are needed for the chemical reactions that convert the pollutants.
Signs of trouble: Key indicators of catalytic converter issues include rattling sounds coming from the exhaust, a rotten egg smell, the ‘check engine’ light coming on, poor engine performance, reduced acceleration, and failing your emissions test.
Maintenance tips: You can keep your catalytic converter going for longer by using premium fuel, cleaning out your exhaust system regularly, and going for long drives to keep air circulating through the system.
Also check for unusual sounds, smells or leaks – and deal with these issues promptly to avoid lasting damage.
Cost breakdown
- Average estimated cost range for parts: £300 to £1,000
- Average estimated cost range for labour: £150 to £300
Engine control unit (ECU)
Description and function: The engine control unit (ECU) is your car’s central computer, which controls the air-fuel mixture, ignition timing, and idle speed, to help your engine perform at its maximum efficiency and capacity. It can also control other electronic systems in your car.
Why it's expensive: ECUs are expensive to replace due to their advanced technology, complex electronics, precise vehicle-specific programming and quality materials.
Signs of trouble: Watch out for poor engine performance, the ‘check engine’ light appearing - and issues with your electrical systems.
Maintenance tips: You can extend the lifespan of your ECU by regularly updating the software, scanning for diagnostic trouble codes (DTCs), and making sure your battery doesn’t have any voltage fluctuations.
Cost breakdown
- Average estimated cost range for parts: £330 to £880
- Average estimated cost range for labour: £110 to £330
Frequently Asked Questions
The most expensive car part to replace is a hybrid or electrical battery. You can expect to pay between £1,100 and £5,500 for parts - and £330 to £880 for labour. Average overall costs run between £1,430 to £6,380.
If you’ve found yourself in need of a new battery, and asking yourself, “Is it time to sell my car?”, webuyanycar can help. Here’s how it works:
- Enter your reg number into our free car valuation tool.
- Book your appointment at any of our 500+ branches.
- Drive to your appointment. Happy to sell? We’ll send the money to your bank.
The automatic gearbox is one of the most expensive parts to repair, as it has so many components - and requires many hours of labour to fix.
Therefore, if you have a broken automatic gearbox, it’s important to consider whether it’s more economically viable to repair or sell your car.
Engine replacements and transmission repairs are two of the most demanding car repair jobs, with timescales ranging from several days to a few weeks.
Rolls-Royce is the most expensive car brand, with models often selling for six-figure sums - and upwards! Other premium, luxury, and high-performance brands include Bugatti, Pagani, Koenigsegg and Ferrari.
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