The 40-Point Used Car Inspection You Can Do Yourself

This does not replace a mechanic. It replaces wasting a mechanic’s time on a car that was never worth inspecting. Twenty minutes with this list eliminates most bad cars before you spend anything.

Before you start the engine

Always inspect a cold engine. A seller who has the car warmed up and idling when you arrive may be hiding a cold-start noise. If it is warm, come back another day.

Exterior — twelve checks

• Panel gaps. Stand at each corner and sight down the body. Uneven gaps mean collision repair.
• Paint texture and colour match, checked in daylight from an angle. Look at the edges of panels.
• Overspray on rubber trim, window seals and inside the door jambs.
• Tyre brand and tread depth on all four. Mismatched brands or uneven wear point to alignment or suspension problems.
• Tyre date codes — the four-digit DOT week/year. Tyres older than six years need replacing regardless of tread.
• Windscreen chips and cracks, particularly in the driver’s sight line.
• Headlight lens clouding, which is a real cost to correct.
• Rust at the rear wheel arches, rocker panels and beneath the doors.
• Every light: headlights, high beams, indicators, brake lights, reverse, fog, and the third brake light.
• Boot floor lifted — check for water, rust and a spare with air in it.
• Bonnet and boot alignment when closed.
• Glass — confirm all panes carry the same manufacturer marking and date.

Under the bonnet — eight checks

• Engine oil on the dipstick: level, colour, and any milky texture, which indicates coolant intrusion.
• Coolant colour and condition in the reservoir. Rusty or oily coolant is a serious warning.
• Transmission fluid where a dipstick exists — bright red is good, brown or burnt-smelling is not.
• Brake fluid level and clarity.
• Belt condition — cracking, glazing or fraying.
• Battery terminals for corrosion, and the battery date sticker.
• Any fluid residue, wet or crusted, on the block, hoses or the ground beneath.
• Signs of recent pressure washing in the engine bay, which is sometimes used to hide leaks.

Interior — ten checks

• Smell first. Mildew means water intrusion. Heavy air freshener usually means something is being covered.
• Damp carpet, especially under the mats and in the footwells.
• All warning lights should illuminate at key-on and then extinguish. A bulb that never lights may have been removed.
• Air conditioning at full cold, and heat at full hot. Test both.
• Every window, lock, mirror and seat adjuster.
• Infotainment, Bluetooth pairing, reversing camera and every speaker.
• Seat wear against the odometer reading. A heavily worn driver’s seat on a low-mileage car is a red flag.
• Pedal rubber wear, for the same reason.
• Both keys present and both working, including the remote functions.
• Boot and bonnet releases from inside the cabin.

The test drive — ten checks

• Cold start. Listen for rattles, knocks or extended cranking in the first fifteen seconds.
• Brake feel — pulsation through the pedal means warped rotors, a spongy pedal means air or a fluid issue.
• Steering straight-ahead with hands loose; the car should track without pulling.
• Transmission shifts, up and down, under both light and heavy throttle. Hunting or flaring is expensive.
• Highway speed — take it above 60 mph. Vibration and wheel-bearing noise only appear there.
• A full-lock turn in both directions at low speed, listening for CV joint clicking.
• A rough road section for suspension clunks and rattles.
• Reverse and an incline hold for the parking brake.
• Air conditioning under load with the engine hot.
• A hard stop from about 40 mph in a safe, empty area to confirm the brakes are honest.

Deal-breakers

Walk away for any of these: milky oil, active check-engine light the seller cannot explain, mismatched VIN plates, a title that is not in the seller’s name, evidence of flood damage such as silt under the carpet or corrosion on wiring connectors, or a seller who will not permit an independent inspection.