Things to look out for when checking the health of your car

Owning a used car is a brilliant financial move, but keeping it in peak condition requires more than just a quick glance at the fuel gauge. While most drivers understand the basics of checking oil and water, your vehicle communicates its health through various subtle indicators. By performing deeper health checks once a month, you can catch minor issues before they escalate into bank-breaking repairs. Here is how to decode your car’s secret language.

Turn your volume button down and listen

Your car will often audibly protest long before a warning light illuminates. Modern vehicles are engineered for smoothness, so any new sound is a cue to investigate.

• Squealing on startup: this high pitched noise usually points to a worn or loose fan belt. It is a relatively inexpensive fix that prevents the belt from snapping and leaving you stranded.
• Grinding when braking: this is a major red flag indicating that your brake pads have worn down to the metal backing. At this stage, you are damaging your rotors and significantly increasing your stopping distance.
• Low speed clicking: if you hear a rhythmic clicking while turning at low speeds, your constant joints are likely failing. Ignoring this can eventually lead to a total loss of power to the wheels.

Does something smell funky?

A healthy cabin should be scent neutral. If you notice a persistent, pungent odor, your nose might be sniffing out a mechanical failure.

• Sweet and syrupy: this is the distinct smell of ethylene glycol, indicating a coolant leak from the radiator, a hose, or the heater core.
• Burnt toast: this often signals an electrical short or burning insulation. Given the fire risk, this requires immediate attention.
• Thick, acrid smoke: This usually means oil is leaking onto a hot exhaust manifold.
• Rotten eggs: A classic sign of a failing catalytic converter or an overcharging battery.
• Raw fuel: If you smell petrol while driving, pull over safely immediately. A fuel leak is a severe fire hazard and usually indicates a compromised fuel line or injector seal.

Decoding the smoke signals

The smoke coming out of your tailpipe is a great window into the health of your engine. On a cold morning, white vapour is normal. However, persistent smoke in different colours usually means trouble deep within the car.

• Blue smoke: the engine is burning oil. This often happens because of worn piston rings or valve seals. Check your oil levels immediately and book a service.
• Black smoke: the engine is burning too much fuel caused by a dirty air filter or a faulty fuel injector. Replace the air filter.
• White smoke: the coolant is entering the combustion chamber. This is a common sign of a blown head gasket. Stop driving and call for roadside assistance.

Tyre wear

Tyres are your only contact point with the road. Beyond checking pressure, the way they wear tells a story about your suspension and alignment. If the tread is wearing unevenly, such as the inside edge wearing faster than the outside, your wheel alignment is likely off. Potholes or curbing a wheel can easily cause this, forcing your engine to work harder and ruining expensive rubber prematurely. Furthermore, if you feel vibrations through the steering wheel at highway speeds, your wheels are likely out of balance, which puts unnecessary stress on your suspension components.

Fluid colours

The color and consistency of your car’s fluids are just as critical as the levels.

• Engine oil: should be amber or dark brown. If it looks like a chocolate milkshake, coolant has contaminated the oil, indicating a serious internal leak.
• Brake fluid: this should be clear or golden. If it looks like cola, it has absorbed excessive moisture and needs to be flushed to maintain braking performance.
• Transmission fluid: it should usually be bright red. If it is dark brown or smells "burnt," the internal clutches may be wearing out.
• Coolant: this should be a vibrant green, pink, or orange. If it appears rusty or has debris floating in it, your cooling system needs a professional flush to prevent clogs.

The battery

Australian heat is notoriously brutal on batteries, often shortening their lifespan to three years. You can spot a failing battery before it dies. Look for white, powdery corrosion (acid salts) around the terminals; this can be cleaned with warm water and baking soda to improve the connection. If your engine cranks slowly when starting, or if your headlights dim while you are idling at a red light, your battery or alternator is likely on its last legs.

Inspecting the rubber bits

The rubber hoses and belts in your engine bay undergo constant heat cycles, eventually becoming brittle.

With the engine cool, give the radiator hoses a squeeze. They should be firm yet flexible. If they feel squishy (rotting from the inside) or brittle with visible surface cracks, they are at high risk of bursting under pressure. Similarly, check the serpentine belt for fraying. A snapped belt results in an instant loss of power steering and causes the engine to overheat almost immediately.

Dashboard

It is a common habit to ignore a "Check Engine" light if the car seems to be driving fine. However, these lights trigger when the car’s computer detects something outside of normal operating parameters. What starts as a $50 sensor issue can quickly spiral into a $2,000 catalytic converter replacement if left unaddressed. Using a diagnostic tool early can save you a fortune.

Stay one step ahead

Taking twenty minutes once a month to perform these deeper checks can make a massive difference. You do not need to be an expert to spot a change in colour, a new smell, or an odd sound. Being proactive about your car’s health ensures that your car stays reliable for years to come.

For more tips on keeping your car safe, check out our guide on how to maintain your car.