How to tell a bargain from a banger

How to tell a bargain from a banger

Holidays are over, Christmas is not yet on the horizon and forecourts are full of pre-owned cars which have been traded in to get the latest “67” plate.

For lots of us, now is the time we think about trading up to a newer model, says Tim Shallcross, IAM RoadSmart head of technical policy.

However, today’s high-tech cars can be concealing wallet-crunching problems unknown on previous generations of motors. Fortunately, you don’t need a degree in electronics or a mobile diagnostic machine. Just follow the advice below and you’ll soon tell a trustworthy bargain from a troublesome money pit.

Service history

Modern engines are staggeringly efficient compared with their predecessors, but proper maintenance is essential to keep them that way. Oil, brake fluid, filters and coolant must all be changed when the manufacturer specifies, otherwise expensive trouble is being stored up for the future.

Ask for the service history and take time to look through it carefully. If the service record is seriously incomplete or missing, walk away, otherwise you could be footing the bill for someone else’s neglect.

Dashboard lights

ABS, SRS, ESC, engine management – every electronic system has a warning light. Make sure they all light up when you turn on the ignition – unscrupulous sellers have been known to remove a bulb to disguise a faulty system.

You may need to turn the ignition on and off a few times before you spot them all. Most should go out within a few seconds, the rest of them when you start the engine and release the park brake (handbrake).

After that, a light means a problem. Don’t be fobbed off with “they all do that” or “that’s normal”. The car has a fault, so walk away.


Listen carefully for the first few seconds – knocks or rattles on start-up can mean trouble. Watch the exhaust smoke; white vapour from a cold engine is normal provided it disappears as the temperature rises.

Black smoke on heavy acceleration means dirty or worn injectors and blue smoke at any time indicates a badly worn engine – often through neglected maintenance. Avoid the car.

Road test

Listen for suspension rattles and clunks over rough roads. Check gear-change smoothness, the cars steers straight ahead and brakes squarely. Try stopping at different rates – gently and rapidly. The engine should never stall as the car stops, nor should the revs drop very low then pick up to the right idle speed. If it does, there’s a problem with the management system.

Learn to walk away

Keep your head and reject a car with signs of problems. Cars are more often an emotional choice than a rational one, but the emotional choice is much more likely to end in tears. If you have any doubts at all, go home and sleep on it.

If the salesperson hints at other buyers on the way, call their bluff – there are thousands more bargains out there.