Buying a used car in Perth? How can you be sure it’s not hiding a nasty surprise? While a vehicle might look immaculate on the surface, many secondhand cars conceal mechanical faults that aren’t obvious until it’s too late. That’s where Spot on Vehicle Inspections comes in.
As a trusted Perth vehicle inspection provider, we specialise in uncovering the issues others miss—saving our customers thousands of dollars and untold frustration. Our team of experienced professionals conducts thorough assessments on used vehicles, offering the insight you need to make a confident purchase. Below are seven of the most common hidden mechanical issues we uncover.
Read: What to Expect During a Perth Pre-Purchase Vehicle Inspection
1. Worn Engine Mounts
Engine mounts may seem like a minor component, but they play a crucial role in stabilising your engine and absorbing vibrations. When these mounts are worn or cracked—usually due to age or excessive stress—they can’t perform properly. The result? Harsh vibrations, unsettling engine movement, and loud clunks when changing gears or accelerating.
This issue is often missed during visual inspections and even test drives. That’s because sellers may temporarily mask the symptoms or they might not be noticeable at low speeds. However, the long-term consequences are significant. Excessive engine movement can strain exhaust connections, wiring, and even other engine components.
At Spot on Vehicle Inspections, we’ve come across countless vehicles where worn engine mounts went undetected until we performed a full underbody inspection. Catching this issue early can save hundreds in future repairs and make all the difference when deciding whether to buy.
Read: Perth’s Best Mobile Car Inspection Services: A Quick Guide
2. Leaking Head Gasket
A leaking head gasket is one of the costliest problems a used car can hide. The head gasket seals the combustion chamber and prevents coolant and oil from mixing. When it begins to fail, it can cause engine overheating, loss of coolant, white smoke from the exhaust, or milky residue under the oil cap.
Unfortunately, unethical sellers may top up fluids or use sealants to hide symptoms during inspections and test drives. It might seem fine when you drive it—but give it a week and the engine could be cooking itself from the inside out.
Our inspectors are trained to spot early signs of gasket leaks through pressure tests, coolant checks, and oil analysis. We’ve seen many buyers walk away from a “deal” after learning the truth. Without a professional car pre-purchase inspection company like us, you may not find out until it’s too late—and by then, repairs can cost thousands.
Read: How to Avoid Common Pitfalls When Buying a Secondhand Car in Perth
3. Transmission Issues
The transmission is one of the most complex and expensive components of any vehicle, and it’s also one of the most commonly overlooked. Whether the car is automatic or manual, hidden transmission faults can be a nightmare to fix.
Common symptoms include:
- Delayed or jerky gear shifts
- Slipping out of gear
- Unusual whining or grinding sounds
- Dashboard warning lights
These issues may not present themselves during a short test drive. In some cases, transmission fluid may have been recently changed to disguise shuddering or noise.
Our inspection team uses diagnostic tools to read transmission codes and assess real-time performance metrics. Even if no warning lights are visible, we can detect underlying issues that indicate wear or future failure. This level of scrutiny is why we’re a top mobile car inspection service in Perth—bringing peace of mind straight to you.
Read: How Often Should You Get a Vehicle Inspection? Perth Experts Weigh In
4. Worn Suspension Components
The suspension system affects everything from comfort to control. It includes shock absorbers, struts, bushings, ball joints, and control arms—all of which wear out over time. The trouble is, a car can still feel “normal” during a test drive even when suspension components are on their last legs.
Our inspectors often find:
- Cracked or perished rubber bushings
- Leaking shock absorbers
- Play in the ball joints
- Uneven ride height
These are easy to miss unless the car is on a hoist and a trained eye is involved. Poor suspension doesn’t just mean a bumpy ride—it can seriously affect braking and handling, especially in emergencies.
By conducting a thorough physical inspection underneath the vehicle, we uncover problems you won’t see from the driver’s seat. This is one of the many reasons buyers trust Spot on for a proper secondhand vehicle inspection.
Read: Why a Comprehensive Vehicle Inspection Can Help You Avoid Expensive Repairs
5. Brake System Wear
Brakes are your vehicle’s most critical safety system, yet they’re commonly neglected. Visual brake pad checks aren’t enough—many issues lie deeper within the system.
Here’s what we often find:
- Warped brake rotors
- Uneven pad wear
- Contaminated brake fluid
- Leaking brake lines
- Sticky callipers
These problems aren’t always evident during a brief drive, especially if the vehicle has been warmed up beforehand. Warped rotors, for example, might only become noticeable under heavy braking. Likewise, moisture in brake fluid reduces effectiveness but won’t cause any immediate symptoms.
Our inspectors use a range of tools—including micrometers and brake fluid testers—to get a complete picture of the system. We assess braking performance and pad life, and check for corrosion or damage to critical components. When safety is non-negotiable, you can’t afford to guess.
Read: Top 5 Red Flags to Look Out for During a Used Car Inspection
6. Faulty Cooling System
Overheating is one of the leading causes of engine failure, and a faulty cooling system is often to blame. The radiator, thermostat, hoses, and water pump all need to work in harmony. But wear, corrosion, and age can lead to leaks or inefficient cooling.
What we look for:
- Coolant stains or puddles under the engine bay
- Cracks in hoses and plastic fittings
- Faulty radiator caps or thermostats
- Discoloured or low coolant fluid
A seller may simply top up coolant before a sale to hide a slow leak or failing water pump. But during our pressure tests, leaks are quickly revealed. We also check for internal leaks using coolant analysis and observe temperature behaviour during engine idle and rev cycles.
Catching cooling issues early can save your engine. That’s why buyers who want complete peace of mind trust our mobile inspections every time.
Read: How to Choose the Right Mobile Vehicle Inspection Service in Perth
7. Electrical Gremlins
Modern vehicles are loaded with electronics—from central locking and infotainment systems to engine sensors and safety modules. But with complexity comes a higher chance of failure. Faulty wiring, corroded connectors, and malfunctioning sensors can lead to expensive repairs.
Symptoms we often detect:
- Inconsistent dashboard warnings
- Central locking or window failures
- Airbag or ABS light intermittently coming on
- Dead battery due to parasitic drain
The average buyer won’t pick up on these problems unless the issue happens during the test drive. And even then, the full scope of the fault won’t be clear.
Our team uses diagnostic scanners to interrogate the vehicle’s onboard computer systems. We can uncover historical faults, pending trouble codes, and intermittent errors that haven’t triggered dashboard lights—yet.
With electronics becoming increasingly crucial, overlooking this area could mean buying a car with hidden, expensive faults waiting to emerge.
Don’t Let Hidden Faults Drive Your Decision
Could your next used car be hiding one of these costly problems? The truth is, even the cleanest-looking vehicles can conceal issues that only a trained professional can uncover. That’s why it pays to get a thorough inspection before signing on the dotted line.
At Spot on Vehicle Inspections, we bring years of experience and a highly personalised service to every inspection. As a leading car pre purchase inspection company, we’re proud to help Perth drivers make smarter buying decisions.
If you’re looking to book a comprehensive vehicle inspection that’s fast, friendly, and fixed-price, contact us today and let our team give you peace of mind.