Test drive checklist for island roads

A short loop round a flat industrial estate tells you very little. Island roads ask a lot of a car in a few miles: steep hills, tight bends, stop-start summer traffic and then a quick run on a main road. A test drive that copies that will find most of the faults that matter. This is the plan to take with you.

Before you set off

• Insurance is sorted. At a dealer, their trade policy usually covers you; ask. For a private car you'll need your own cover, such as a short-term policy. "Driving other cars" cover on your own policy rarely applies to a car you don't own.
• The engine is cold. Put your hand on the bonnet. A warm engine can hide a slow start, smoke or a rattle that only lasts a minute.
• You've checked the MOT history. If it mentions brakes, suspension or an oil leak, you know what to listen for. How to read it.
• Your licence is with you and the seller is in the car. Don't hand over your keys or your own car as "security" to a private seller.

The cold start

Turn the key to the first position and watch the dashboard. Every warning light should come on, then go out within a few seconds of starting. A light that never comes on at all can mean a bulb has been taken out to hide a fault.

• It should start straight away and settle to a steady idle within a minute.
• Look at the exhaust. A little white vapour on a cold day is normal. Blue smoke (burning oil) or thick white smoke that doesn't clear (possibly coolant) is not.
• Listen for a rattle in the first few seconds. On some engines that's a worn timing chain, which is an expensive repair.

Plan the route: five kinds of road

You don't need a long drive, just a varied one. Ask the seller to suggest a loop that includes each of these, or plan one yourself before you go.

In town: gearbox, clutch and idle

• Every gear goes in smoothly, including reverse. A crunch going into second or third points to a worn synchromesh.
• The clutch bites around the middle of the pedal's travel. A bite right at the top often means the clutch is near the end of its life. On many cars that's a £500 to £1,000 job, more if the flywheel goes too.
• On an automatic, changes should be smooth and quick, with no thump into Drive or Reverse and no hesitation pulling away. What to check on a used automatic.
• The temperature gauge should rise to the middle and stay there, even in a queue.

The hill start: the island's best test

Stop on a steep hill, hold the car on the handbrake and pull away. Then do it once more a bit more briskly.

• The handbrake holds the car on the slope without being pulled up hard. Electronic handbrakes should release cleanly as you pull away.
• The revs don't flare without the car moving faster. That is clutch slip, and hills show it far sooner than flat roads do.
• No judder through the floor as the clutch takes up.
• It pulls cleanly up the hill in a sensible gear, without hesitating, misfiring or flashing a warning light.

Narrow lanes and rough roads

A stretch of bumpy lane or a few speed humps will tell you about the suspension and steering.

• No knocks or clonks over bumps. These usually mean worn drop links, bushes or ball joints. They're not always expensive, but they add up.
• Turn the wheel to full lock at walking pace both ways. A clicking noise often means a worn driveshaft joint.
• Steering feels tight, with no clunk or vagueness around the straight-ahead.

A faster road

Get up to 50 or 60mph on a main road if you safely can.

• No vibration through the steering wheel. It can be as simple as wheel balancing, or a sign of a bent wheel or worn parts.
• No humming or droning that rises with speed. That can be a wheel bearing or uneven tyres.
• The car runs straight when you relax your grip on the wheel (on a straight, level road).
• Cruise control, speed limiter and lane assist work, if fitted.

Brakes

When it's safe and there's nothing behind you, brake firmly from about 30mph.

• It stops straight, without pulling to one side.
• The pedal is firm, not spongy, and doesn't sink.
• No juddering through the pedal or steering wheel. That usually means warped discs.
• No grinding or squealing. Grinding means the pads may be worn down to the metal.

Back at the start: the hot check

Don't switch off straight away. Leave the engine running for a minute, then:

1. Look at the dashboard againNo warning lights should have come on during the drive.
2. Look under the carDrips of oil (brown or black), coolant (often pink, green or blue, and sweet-smelling) or brake fluid are all worth asking about. Clear water from the air conditioning is normal.
3. Open the bonnetListen for hissing, and smell for burning oil or coolant. Don't remove the coolant cap on a hot engine.
4. Try the air conditioningIt should blow cold within a minute or two. A re-gas is cheap; a new compressor isn't.
5. Switch off and restartA hot restart should be as easy as the cold one.

If something isn't right

Ask a dealer to fix the problem before you buy, or to take the cost off the price, and get either one in writing. If you buy from a dealer, you also have strong legal rights if a fault shows up later.