As with your visual inspection of the car, you can identify many problems without needing much mechanical knowledge.
Try to start the engine yourself – it should start first time. Check for any significant amount of smoke or steam from the exhaust – a little is normal, especially on a diesel, but loads of blue smoke (for example) could indicate an expensive problem.
During The Test Drive
The seller will probably continually talk to you during the test drive. Feel free to ignore them and concentrate on the drive. It can be difficult to choose your own route, but try to ensure that you do the following:
Use all the gears, including reverse. Make sure they engage cleanly and that the vehicle doesn’t jump out of gear or make strange noises. The engine should pull smoothly in all gears.
Use the steering on full lock, ideally in both directions. Listen for creaking or other strange noises; there shouldn’t really be any.
Is the car’s steering nicely balanced when going straight, or does it pull to one side? This isn’t right.
Try to test all of the electrics (possibly while stationary, doing this while driving could be dangerous):
- Windscreen washer and wiper
- Electric windows / sunroof
- Air con
- And so on – if it’s fitted, try to test it. Electrical fittings can be expensive to fix.
Make sure you give the brakes a good try. Monitor them for any juddering, vibration or noises. If the steering wheel wobbles when you brake hard, the front brake discs are probably warped and need replacing.
Likewise if the vehicle pulls to one side when braking, something’s amiss. Either insist on it being fixed (if buying from a dealer) or get an estimate to have it fixed (if buying privately) before going ahead with a sale.
(An initial light grinding noise when you first start driving is probably ok – its just light rust and dirt being rubbed off the discs. This happens if a car has been parked for a few days. However, if the noise continues for more than a few minutes, the discs may be badly corroded and need replacing or the brake pads may be worn out).
Finally, try to assess the car’s comfort and performance. Do you like it? Is it what you want or need?