What’s that sound? You’re driving along, music playing, everything feels fine, and then your car makes a noise you’ve never heard before. Something clunks, screeches, ticks, or hums in a way that immediately grabs your attention. Suddenly, you’re listening more closely, volume down, eyes darting to the dash. Is that normal? Is something about to fall apart?

Unusual car noises are never something to ignore. They’re often your vehicle’s way of letting you know something’s not quite right. But interpreting those sounds can be tricky unless you know what you’re listening for. Here’s a breakdown of some odd noises drivers often report and what a mechanic might say when they hear about them.

​​1. The engine’s making a loud knocking noise

This one can be jarring. It often shows up when you’re accelerating, and it sounds like something is rattling or knocking around under the bonnet.

A car mechanic hearing this might immediately think of engine knock, a problem that’s often tied to how fuel is burning inside your engine. Sometimes it’s poor-quality fuel, other times it might be a sensor issue or carbon buildup. If it’s happening regularly, they’ll want to look at the timing, check the spark plugs, and possibly test the fuel system. Either way, it’s not something you ignore. That kind of knocking can wear your engine down fast.

2. A squealing sound just after you start the car

If it’s cold and you hear a high-pitched squeal as the engine kicks in, don’t be surprised if your mechanic raises an eyebrow before checking the belts.

They’ll probably be thinking about the serpentine belt — the one responsible for powering your alternator, aircon, power steering, and more. If it’s loose or worn, it can start squealing, especially in cold or damp conditions.

It’s not urgent in the first few moments, but if it keeps happening or gets louder, the belt might be close to failing. And if that snaps while you’re driving? You could be stuck on the side of the road without power steering or charging.

3. Clicking noises when turning corners

This usually happens at low speeds, when you’re turning sharply, like pulling into a parking space. A repeating click, click, click from the front wheels.

Most mechanics will instantly suspect a worn CV joint, especially if the sound is only there while turning. These joints connect your transmission to the wheels, allowing them to move up and down with suspension and side to side with steering. If the protective boot gets damaged, grease leaks out, and dirt gets in, leading to wear.

The clicking is one of the early signs. Catch it soon, and it’s a relatively simple fix. Leave it, and you risk the joint failing entirely, and that’s a much more expensive problem.

4. Brakes groaning or moaning

Not a squeak — more of a deep, uncomfortable groaning sound when you hit the brakes, especially at low speeds or coming to a stop.

The moment you describe this, a mechanic will probably ask how long it’s been since the brakes were checked. That groaning is often metal rubbing on metal, which is a sign the brake pads have worn all the way down.

When that happens, the backing plate starts grinding against the rotor. It not only damages the rotor, but it also means you’re driving with reduced braking power. Most mechanics will tell you this is one of those noises you don’t wait around with. Get it looked at straight away.

5. A humming that gets louder the faster you go

You’re driving along, and there’s this steady hum or drone that rises with your speed. It doesn’t go away, but it also doesn’t feel like it’s coming from the engine.

Mechanics hear this kind of description all the time and often head straight for the wheel bearings. These allow the wheels to rotate freely, and when one starts to wear out, it can create a low hum that gets louder as the car moves faster. It’s one of those sounds that drivers tend to ignore for a while, but it’s definitely not harmless. A failed bearing can damage your hub, affect steering, and in extreme cases, cause the wheel to seize up completely.

6. Rapid ticking from the engine area

This one can be subtle or sharp, but it’s usually a fast, rhythmic ticking that speeds up with the engine. Sometimes you’ll hear it more clearly when the car is idling or just after starting.

Mechanics will often start by checking your oil. Low oil levels or thick, dirty oil can stop the lifters and valves from being properly lubricated. That’s where the ticking can come from.

But if the oil checks out, they’ll be looking deeper, possibly at valve clearances or worn parts inside the engine’s top end.

It’s not always urgent, but it is something you want to stay on top of. Letting it run too long could mean real damage to the engine over time.

How to Talk to Your Mechanic About Noises

You don’t need to know the names of the parts or guess the cause. But it does help to give your mechanic a few details. Think about:

• When the noise happens — just after starting? When braking? During turns?
• Where it seems to be coming from — front, back, left side, engine bay?
• What it sounds like — ticking, squealing, humming, groaning?

These clues can speed up the diagnosis. You don’t need to record it (though that doesn’t hurt), but being able to describe it clearly can make a real difference.

Don’t Wait for It to Get Worse

If your car is making an unusual noise, chances are it’s trying to tell you something. Some issues are minor at first — a bit of wear, a part that’s just starting to go. That’s when repairs are usually cheaper and simpler.

Ignore the sound and keep driving, and you might end up dealing with a breakdown, or a much bigger repair bill.