What to Check When Buying a Used Car, in the Order That Matters

Most used car checklists are a long list in no particular order, which is why people arrive, look at the paint, sit in it, and drive home having checked nothing that costs money to put right.

What to check when buying a used car is really a question about sequence. The order below puts the expensive and hard-to-fix things first, while you are still capable of walking away, and leaves the cosmetics until last where they belong.

Before you go: check the paperwork exists

Ask for the registration document, the service history and the inspection certificates before you travel. A seller who cannot produce them before you arrive is unlikely to produce them when you are standing in their driveway having driven an hour.

Check the seller's name matches the registration document, and that the mileage on recent inspection records climbs sensibly. A mileage that jumps backwards, or a year with almost none in a car that has otherwise done twelve thousand annually, is a question rather than an accusation, and the answer tells you a lot.

Arrive early, and look at it cold

Ask to see the car before it has been started, and get there early enough that the seller has not warmed it up for you.

A cold start reveals what a warm one hides: smoke on the first firing, a rattle that disappears once the oil is up, a battery that struggles. If you arrive to find the engine already warm on a car you were told had not moved, that is worth noting rather than ignoring.

Look underneath and behind, not at the paint

The expensive faults are structural and they hide in the places nobody photographs.

• Crouch and look along each side in daylight. Ripples in a reflection mean panel work.
• Open the boot, lift the carpet, look at the spare well for rust, water or crumpled metal.
• Look at the inner wings under the bonnet and at the sills behind the front wheels, which is where corrosion starts.
• Check the panel gaps are even on both sides, and that the bolts holding the wings have not been disturbed.
• Look at the tyres: mismatched brands, uneven wear across a tread, or four different dates suggest either neglect or something eating tyres.

None of these prove anything on their own. Together they build a picture, and the picture is usually accurate.

Fluids and the engine bay, in two minutes

You are not diagnosing an engine here, only looking for the obvious.

Pull the dipstick: oil should be present and not gritty. Look at the coolant: it should be coloured and clear rather than brown or oily. Look for crusty residue around hose joints and for a film of oil on the block that suggests a leak has been running long enough to collect dirt.

Then look at the underside of the oil filler cap. A thick pale emulsion there can be nothing more than condensation on a car doing short journeys, and it can also be something serious, which is exactly why it is a question to ask rather than a verdict to reach in a driveway.

The drive, and what to do during it

Drive it properly, not around the block. You want a range of speeds, a rough surface, some braking and at least one full-lock manoeuvre.

With the radio off and a window down: listen for a hum that rises with speed, feel for a vibration at motorway speed and for any shudder when braking. On a manual, take it to third and pull away from low revs to feel whether the clutch bites cleanly. On an automatic, feel whether the shifts are smooth or jerky when cold.

Brake firmly once, somewhere safe with nothing behind you. The car should stop straight without pulling, and the pedal should feel firm rather than long.

Check every warning light comes on with the ignition and goes out after starting. A bulb that never illuminates has often been removed rather than fixed.

The questions worth asking out loud

Some of the most useful information comes from asking directly and watching how it is answered.

• Why are you selling it?
• What has gone wrong while you have owned it?
• When were the tyres, brakes and battery last replaced?
• Has it ever been in an accident, however minor?
• Is there anything you would want to know if you were buying it?

The last one is the most revealing. An honest seller usually volunteers something small, and a seller who says absolutely nothing at all on a car with a few years behind it is either unusually lucky or not telling you.

What to do with what you found

Almost every used car has something. The question is not whether you found faults but whether you found the kind that change the price or the kind that change your mind.

Tyres, brakes and a battery are wear items with knowable costs, and they are legitimate to negotiate on. Corrosion in structural areas, evidence of accident repair, a mileage history that does not add up or an engine that is not right are reasons to walk away rather than haggle.

If you like it and you are unsure, a paid independent inspection costs a fraction of a bad purchase, and a seller with nothing to hide will not object to one. Being told no to that request is itself an answer.