Death, taxes, and cars making unusual noises. Well, if Benjamin Franklin had lived to own a car in 2018 he would confirm that cars making strange noises is the third certainty in life.
The fact of the matter is, there are so many moving parts inside your car that when one of them becomes worn or falls out of whack, it’s going to cause a domino effect that will be heard throughout your cabin. To help you understand what those sounds mean, we’ve compiled a list of 7 Common Car Noises to Listen out for when you’re driving.
1. Squeaky Brakes
Why do my brakes squeak? Why do my brakes make noise when coming to a stop? The most common questions when it comes to car noises revolve around brake noise. Naturally, brakes are subject to more wear and tear than any other component in your vehicle, which means that they are the first to show signs of wear through the noise.
There are a few reasons why your brakes might squeak or squeal when coming to a stop. The most common reason by far is worn brake pads. Brake pads have a small metallic finger attached to them, that, once worn, contacts your brake disc rotor, making that dreaded squealing sound when coming to a stop. This is done intentionally for the exact purpose of making it clear your brakes need attention. If you have noticed this sound coming from your car, it’s advisable to have your brakes checked as soon as possible. Worn brake pads can also cause undue wear to brake rotors.
The other (less common) causes of brake squeal are Glazed Brake Pads. This is caused by the brake pads being heated to a temperature beyond their normal operating range, causing the pad material to break down and adhere to the disc surface. As a result, two surfaces of equal hardness come into contact. The solution? Well, you can either have your brakes machined or, for a similar price and greater assurance of future reliability, replace your brake rotors.
Performance orientated brake pads are prone to squealing when cold, is designed to cope with higher temperatures they are made with quite a hard compound though this is usually evident immediately after the pads are installed.
2. Knocking Noise from the Engine Bay
Unless you’re driving a Tesla or fully electric car, your engine will make noise. But, how much engine noise is acceptable? If your engine is producing more noise or juddering at idle, the first step is checking your oil. It can sometimes be one of the first signs of a bad transmission so it is imperative that you get it checked as soon as possible.
The fact is, the noise could be caused by any myriad of factors. Happily, cars are heavily computerised these days which means that a simple engine scan can probably diagnose the root of the issue before you start throwing money at your car trying to fix things.
3. Loud Knocking Noise After Starting Car
A loud knocking noise after starting your car is a tell-tale sign of oil starvation or worn internal bearings. Your first point of call should be checking the oil level. If the oil level is fine, consider when it was last serviced and have a service performed if it requires one.
In some cases, a loud knocking noise after starting your car can be caused by a poor-quality oil filter (read: an oil filter without an anti-drain back valve), or a partially blocked oil pickup. If your car has enough oil and you’ve recently had it serviced, head back to your point of service to have the issue checked out.
4. Knocking Noise When Driving Over Bumps
Banging noises when driving over bumps can make you dread every speed hump or pothole on the road. A banging noise when driving over bumps can be one of the most irritating rattles in your car, and, once it starts, it’s probably not going away.
Your vehicles suspension system is designed to absorb rough terrain and adjust when driving over uneven surfaces to ensure a safe and comfortable ride for you and your passengers.
Common causes can include worn out shock absorbers, shock absorber mounts, sway bar links or ball joints. It’s not unusual for these parts to wear and are readily available for most vehicles, though the noise can be tricky to isolate. It’s best to have it looked at sooner rather than later as leaving it can result in haphazard handling and accelerated tyre wear, costing you more money down the track.
5. Steering Noise at Low Speed
Steering noise at low speed can be caused by several things. The first (and most likely reason) is the air becoming trapped inside your power steering system. This usually comes about due to a lack of power steering fluid in the reservoir, requiring a top up and a system bleed. Don’t fret, changing your power steering fluid or topping up power steering fluid isn’t an expensive procedure.
The less common, more dramatic cause of this sound is a failed power steering pump. If the system bleed has not cured the noise, this is the most likely cause.
6. Hissing Under Car
Car hissing noises are usually associated with vacuum leaks from one of the many hoses in your car’s engine. So, if the hissing noise is coming from under the car, we can deduce that the hissing is likely coming from the biggest pressure chamber in your car- the exhaust system.
Checking for exhaust system leaks isn’t for the faint-hearted. The easiest (read: not the safest) way to check for exhaust system leaks involves a dense rag and gloves.
Step 1: Block the exhaust system by holding a dense rag against your vehicles exhaust tip to stop gasses from escaping.
Step 2: Listen for hissing or puffing underneath the car. Hissing or puffing underneath the car indicates that there is a leak somewhere along with the exhaust system- robbing your car of efficiency and power.
Fixing a leaking or hissing exhaust can be as simple as replacing a gasket, but in more extreme cases you could require welding or complete replacement of your exhaust. Some cars have design faults that cause this. A good example of this is the exhaust on an AU Ford Falcon 4L, which is prone to cracking after the headers near the driver door.
Another indication your exhaust has seen its day is a rattling underneath the car when running. What your hearing is the material inside your muffler (or Catalytic converter) falling apart and being bounced around inside the exhaust. Again, if you’re unsure or not confident its always best to have a mechanic check it for you properly.
7. Clunking Noise When Turning
Clunking or knocking noises when turning is one of the most disconcerting (read: annoying) noises that you can experience in your car. A knocking noise when turning can be attributed to several different causes, all of which are usually related to a failed component in your vehicles suspension system. Not only are steering knocks annoying, they can also compromise the handling and safety of your vehicle.
Common causes of steering knocks:
Broken Sway Bar Link – A sway bar or ‘anti-roll bar’ is designed to reduce body roll when your vehicle turns. Naturally, sway bar links are placed under enormous stress and are usually one of the first components in your vehicle to give up. If your vehicles sway bar is broken or damaged, it will emit a clunking or knocking noise when going over bumps.
Worn Ball Joints – Ball joints are the link between your vehicles wheels hubs and the rest of the suspension components. Ball bearings are one of the most important components in your vehicles suspension system, so, when one breaks, you may notice a clunking noise coming from the front wheels that becomes increasingly noticeable the further you turn the steering wheel. In addition to a knocking noise from the front wheels, you may also notice increased vibration coming through the steering wheel.
Bad Tie Rods – Tie rods are the connecting point between the steering rack and the steering arm. Tie rods are responsible for controlling the movement between the steering wheel and the front tyres. When a tie rod becomes worn or loose, it may produce a loud clunking noise when your steering is on full lock and increased play in the steering wheel.