What should I check when viewing a used car?
A walk-round that finds accident repairs, neglect and a hidden cold start, and the drive that reveals what the walk-round cannot.
- Difficulty
- intermediate
- Time
- 1 hr
- Read
- 4 min
- Safety
- caution
Short answer
Insist on a cold start, check panel gaps and paint finish in daylight, look for mismatched tyres and uneven wear, and drive it far enough to reach motorway speed. Most problems announce themselves in the first ten minutes if you are looking.
You are not trying to diagnose faults. You are trying to decide whether this car has been looked after, and whether anything is being hidden from you.
Safety
What you'll need
- Daylight
- A torch
- A magnet wrapped in cloth (optional)
- A tread depth gauge (optional)
Step by step
- Insist the engine is cold when you arrive.Feel the bonnet before anything else. A warm engine hides difficult starting, smoke on start-up and noises that only appear cold. If it is warm, arrange to come back.
- Stand back and look along the car.From each corner, along the flanks. Reflections show ripples, filler and repaint that are invisible from a metre away. Panel gaps should be even and consistent side to side.
- Compare paint colour panel by panel.Look at the car from an angle in daylight. A slightly different shade or texture, or overspray on rubbers and in the door shuts, means a repair. Not fatal, but worth asking about.
- Check all four tyres and the spare.Same brand across each axle, even wear, no cracking, decent depth. Four odd tyres of different makes is a strong signal about how the car has been maintained.
- Look in the boot well and under the mats.Water, rust, a damp smell or a crumpled floor edge. This is where flood damage and rear-end repairs show themselves.
- Start it cold and listen.Blue smoke suggests oil burning, white persistent smoke suggests coolant, black suggests fuelling. Rattles that fade after a few seconds may be normal; ones that persist are not.
- Check every electrical item.Windows, mirrors, central locking with both keys, air conditioning, heated seats, wipers, all lights, the radio and the infotainment. Electrical faults are tedious and expensive on modern cars.
- Drive it properly, including a fast road.Twenty minutes at least, including motorway or dual carriageway speed. Many faults only appear warm and at speed. A five-minute drive round the block proves nothing.
- Feel for anything that pulls, vibrates or wanders.On a straight, level road with hands relaxed. Do not diagnose it — just note it as a reason to negotiate or walk away.
- Check the paperwork against the car.V5C name, address and VIN against the VIN stamped on the car. Service book stamps against the MOT mileage record. Two keys, the locking wheel nut key and the handbook.
- Look at the interior wear against the mileage.A worn steering wheel, shiny seat bolsters and worn pedal rubbers on a supposedly low-mileage car do not match. Wear is much harder to fake than a number.
- Take photographs while you are there.Of anything you want to think about later, and of the V5C and the VIN plate. It is also a reasonable check on a seller's reaction.
Tips
- Take someone with you. A second pair of eyes and a witness both matter, and it makes it much easier to leave.
- The MOT history you checked before travelling is your script — ask directly about anything on it.
- Bring a torch even in daylight. Boot wells, wheel arches and engine bays are dark.
Common mistakes
- Accepting a car that has been warmed up — Cold starting is where oil burning, smoke, misfires and noisy components reveal themselves. A seller who warms the car before every viewing is removing your best diagnostic moment.
- Only driving round the block — Gearbox, cooling and running faults often need twenty minutes and some speed to appear. A short drive at low speed confirms almost nothing.
If it doesn't work
Overspray on rubber seals or in door shuts
Cause: A repaint after accident damage — Fix: Ask directly, and check the history report for a write-off marker. A tidy repair is not a dealbreaker; a hidden one is.
Blue smoke on start-up that clears
Cause: Oil passing valve stem seals — Fix: Note it and factor it in. It gets worse and it is a significant engine job.
Damp carpets or a musty smell
Cause: A leaking seal, blocked drain or worse — Fix: Water in a modern car finds electronics. Treat it as a serious problem unless the source is obvious and trivial.
Service book stamps look identical and recent
Cause: Possibly filled in at once — Fix: Ask for the underlying invoices. Real servicing leaves a paper and card trail, not just stamps.
Questions people ask
Should I pay for a professional inspection?
On an expensive car, an unfamiliar model, or if you are not confident, yes. It costs a fraction of the purchase price and inspectors get under the car properly, which you should not.
How long should the test drive be?
At least twenty minutes, including a fast road, some slow manoeuvring and a few full-lock turns in a car park. Ask the seller to sit in the passenger seat rather than driving first.
What does mismatched tyres tell me?
Usually that the car has been maintained on the cheapest option available at the moment each tyre failed. It is a good proxy for how everything else has been treated.