In 2023, cars are pretty good. It’s part of the reason why drivers are keeping their cars for longer than ever. Okay, so maybe inflation is also a problem there. But the fact that fewer drivers are forced into a new car is also a result of decades of improvement. Most transmissions and nearly all engines are capable of exceeding six-figure mileage targets with just basic maintenance. And for the modern cars that can’t, it’s often the cheapest parts that cause the biggest problems.

A cheap $20 part can cause terminal engine problems in a VW

Volkswagen is the largest auto group in the world, but with that volume comes quality control issues. And in many Volkswagen engines of the 2010s and even 2020s, a $20 part can cause complete engine failure.

The camshaft seal does exactly what it says: it seals the end of the camshaft where it meets the block. However, these seals are notorious for failing in VW’s EA888 2.0-liter turbo as well as its Common-Rail TDI engines and even the 2.8-liter V6s. At $20-$25, it’s one of the cheapest parts on the engine, but it also causes the biggest problems.

When the camshaft seal fails, oil leaks from the engine onto the timing belt. Not only does this result in oil loss and lower oil pressure, but the slick belt can start to slip. You’ll immediately notice performance problems, and if left unchecked the engine will lose enough oil to cause a complete engine failure.

A $20 HVAC actuator can cost thousands to replace

Computer-controlled HVAC systems are great for simplifying the layout of the dash. But the problem is that they are often buried deep under the center console. Responsible for controlling the temperature of the air from your vents, the HVAC controller is a critical component.

It’s not just for comfort – the little black box is also responsible for window defrosting and defogging. So when this cheap part breaks, it’s a big problem that needs to be fixed.

However, it’s more than just a $20 part. Sure, the piece itself is cheap. But because they are controlled electronically, they’re often buried deep within the dash. That means hours of teardown just to replace this box. And with shop labor costs, that $20 part may cost upwards of $1,000 to replace.

Turbo seals are the cheapest car part that causes big problems

These days, a majority of modern cars have turbocharged engines. It’s an easy way to add efficiency without diminishing performance. However, turbocharged cars also have more complex parts, and it’s the cheapest of these components that is the biggest problem.

A turbo seal can cost as little as $3, but when this part fails, you’re looking at thousands in damage. Garrett Manufacturing states that a failed turbo seal will not only starve the turbo of oil, but it can even cause an engine fire in the wrong circumstances. When that hot oil leaks onto a glowing-hot turbocharger or exhaust headers, it can ignite and burn an otherwise functional car to the ground.

Replacing a turbo seal is no easy task, but it’s less costly than writing off an entire car for a $3 part.