10 Most Expensive Car Parts to Replace

We’ve all felt it before – that sinking feeling in the pit of your stomach when you realise something is not quite right with your car and you’re going to have to pay someone else to repair it. This is especially for all the owners of older cars out there. It’s a unique club characterised by the nagging feeling in the backs of our heads that something someday is going to go catastrophically wrong.

No car is immune from an expensive fix – from the most reliable makes to the most exotic, old and new. Whether it was caused by bad luck, bad manufacturing, or our own bad driving or maintenance habits, we all want to know how much it’s going to cost us to fix. It’s good to know a ballpark figure before you head down to the mechanics.

What are the most expensive car parts to repair?

Our survey of motorists who had recently taken their vehicle for a service found that 58% had to pay for repairs they weren’t expecting, while 78% said they were wary of being ripped off – which is natural when you don’t know much about car parts and maintenance. To help with that, let’s go over some of the most expensive car parts and what they will cost you.


A broken cylinder is a hallmark of continued neglect and ignoring previous warning signs like multiple misfires. If you get regular services you should never end up with cylinder failure. Scheduled maintenance ensures you won’t end up with an $8,000 (or greater) mechanic’s bill for repairing a cylinder.

Hybrid car parts

That’s right, the expenses for hybrid cars don’t stop once you fork out the cash to buy them. Parts aren’t readily available, so they’re expensive, and you’ll have to wait for the part to be shipped in. One problem that is hard to detect is inverter failure, since the only warning sign is the “check engine” light. It doesn’t often happen, but when it does, a replacement costs between $4,000 and $7,000 depending on the model.

Lithium ion battery (for an electric car)

Lithium ion batteries experienced a boom in 2015 and 2016 as Tesla and other electric car manufacturers ramped up their production. As technology develops, these batteries will get cheaper and cheaper, but for now they are very expensive. A lot of batteries cost around $150 per kWh and can easily skyrocket from there. Considering a Tesla Model S is equipped with an 85kWh battery, a replacement can be eye-wateringly expensive. The good news is that lithium ion batteries are reliable, and costs are likely to fall dramatically by the time you will need a replacement.


It’s unfortunate that transmission is one of the most important parts of your car, because it is expensive to repair or replace. According to Auto Service Online, automatic transmission failures are caused by fluid problems nine times out of 10. Transmission fluid doesn’t need to get changed as frequently as oil, so lots of car owners forget about it if they’re not getting regular services. You can wear out the transmission in a manual by riding the clutch or unnecessarily changing gears too often. Transmission repairs can cost around $1,000 to $2,000 and a replacement for the whole assembly costs up to $4,000.


A blown engine is about the worst news that your average car owner could receive. Normal engine issues are the most common car problem reported to mechanics. But a ‘blown motor’ means the engine has suffered so much internal damage that it needs extensive repair or a full replacement. An engine replacement can cost between $1,000 and $4,000 depending on the type of engine.

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The camshaft controls how your engine takes in air. It generally won’t break unless you neglect your servicing and oil changes and let grime and dirt build up on the valves. A replacement camshaft is highly labour-intensive, so it can cost between $1,500 and $3,000.

Head gasket

The head gasket is vital because it seals the engine cylinders and stops coolant and oil from leaking. When the head gasket blows, it takes a lot of stuff out with it. You’re looking at an overheated engine, leaking coolant and oil, and white smoke from the exhaust. The gasket itself is cheap enough, but the labour is hard work. Repairs can cost around $1,000 to $2,000.

Mass air flow sensor

The mass air flow sensor measures the amount of air sent to the engine and decides how much fuel to send to the engine in response. Failure of the sensor typically means that you didn’t replace your air filters regularly. Replacement air filters cost around $25. Replacement mass air flow sensors cost around $400.

Car keys

Remember the days when a copy of your car key would cost you $10 from the Mister Minit or the locksmith? Those glory days are over. A replacement electric car key has to be ordered, cut and coded, and it can cost anything from $250 to $750. And if you’ve lost all the keys to your car, then you need to create and code an entirely new set of keys and have the entire car computer reset to match. This can cost around $2,000 to $5,000 and can usually only be done at a dealership, instead of a third party. Perhaps the highest cost is that you’ll have to spend time off the road while you wait for it all to get done.

Air conditioning compressor

The air compressor is what separates high and low pressure air for cooling down your car and engine. A compressor replacement costs around $200 to $600 depending on your car model. If you also need Freon charging, that costs another $100.

An honourable mention…

An honourable mention goes to the seemingly innocent timing belt. Many car manufacturers require this unit to be replaced every 100,000km, and can cost anywhere from a couple hundred up to a couple thousand for luxury cars. Though failures in their expected lifetime are rare, the importance of proper maintenance is critical here.

A useful thing to identify is if your car has an interference or non-interference timing belt. Interference belts mean that if it snaps, you can wave goodbye to many other components in your car. In this case, it’s going to cost a lot more than to just replace the timing belt. Often an entire engine overhaul is necessary. Scheduled replacement of the timing belt can save you a lot of heartache in the long run.

Top tips for proper car maintenance

Most car problems can be easily and cheaply fixed if they are detected as soon as possible. This means getting your car serviced regularly, and doing whatever other maintenance and routine checks you can do yourself. Unfortunately, more than half (55%) of motorists we surveyed about car servicing said they take as long as they can between services to save money. However, with a lot of things in the automotive world, prevention is the best cure, and regular maintenance is the best way to prevent financial catastrophe.

Car Maintenance Tips

A mechanic can only do so much though. Proper car maintenance starts at home in your garage. There are a few things you can do at home to make sure your car is running well:

  • Check the air pressure in your tyres regularly and top up when necessary. This also lets you check tread depth.
  • Check all your fluids regularly, and check the garage floor if there are any leaks. The last thing you want is a power steering failure. Fluids can be topped up with the right fluid from the auto store. Consult your car’s manual for the correct type of fluid – it’s easy to get the wrong one!
  • Check lights regularly. Spare bulbs can often be found at the auto store and while broken lights won’t stop you operating your car, it is a safety issue and can result in a fine from the police.

Industry research by Drive shows that a big problem you face with replacements is the huge mark-up on spare parts. Even replacing a tail light can cost upwards of $600 if you own a 4WD or a luxury car. It’s cheaper to buy a replacement part from an auto store or your mechanic if you can, rather than the manufacturer. Many of these third-party parts will be acceptable under your warranty and insurance policy, but it’s best to check the conditions for any exceptions.

Out-of-Warranty? Look elsewhere!

If your car is out of warranty, then this opens up some freedom for servicing and parts. There are several things you can do with your car out-of-warranty than when it’s in warranty:

  • Use non-genuine parts or hunt online for parts overseas, which can be much cheaper
  • Use any mechanic you like
  • Do your own basic maintenance like oil changes

Serious issues? Time for a mechanic…

For any more serious concerns, it’s best to consult your trusted local mechanic for peace of mind. Car parts can be expensive, but you can easily get more life out of them with regular maintenance. This starts with you at home with basic checks to identify problems before disaster strikes. Taking methods to ensure problems are nipped in the bud can save you a lot of money and heartache in the long run.

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