After inspecting with your eyes, it is time to take the car out for a spin to test out its mechanical bits. Remember to go slow as you get used to the car.
The first thing to do is to check that the engine starts properly without any prolonged cranking. Anything more than 3 seconds and you should probably walk away. Difficulty to start a car might be attributed to a weak battery or faulty starter motor. However, it can also be an indication of more serious engine issues.
After the engine has warmed up sufficiently, it should be idling around 850rpm. Disengage the transmission and get someone to step on the accelerator hard a few times and check that the car is not spewing any blue smoke.
Brakes
Before you start the car, step on the brake pedal. After the car has started up, you should feel the brake pedal depress if it has power or served brakes. Step on it hard now and if the pedal sinks much further, there could be something wrong with the master cylinder.
During normal driving, as you brake, take note of any vibrations. This could mean that the brake disc could be warped and might need replacement. Listen for any screeching noise as well when braking, this indicates that the brake pads might be worn.
The first thing to test for an automatic transmission car is engagement time between the shifting and the gears engaging. It is normal for most automatics to have a slight delay when changing between gears. However. This delay should not be longer than 1 second. If the delay is long, it indicates a transmission problem.
To test, first step on the brake pedal and shift the transmission to "D" or Drive. The shifting should be smooth and not accompanied by any major jerks. Some minor jerking is fine though.
Now as you take the car out for a drive, check that the car accelerates smoothly and the gear changes smoothly and accordingly. If there is any shudder or delay in the shifting, it indicates that the transmission could be worn out. Also, if a gear refuses to up-shift on a level road, it could also mean that the transmission is faulty.
Also, beware of slipping. This means that the gearbox's torque converter is dodgy and the engine's torque does not transmit properly to the drive shafts. You will know this when you step on the accelerator hard and the engine rpm goes up but the speed remains the same.
Manual Transmission
There are two things to look out for when it comes to manual gearboves - the clutch and the gearbox's sycromesh.
For the clutch, take the car out for a drive to make sure that the clutch isn't slipping. Slipping occurs when you accelerate off the line, disengage the clutch pedal but the car doesn't take off cleanly even though the engine is revving. Accelerate through the gears and each time you release the clutch pedal to engage a higher gear, the increase in engine revs should correspond to an increase in road speed.
A worn syncro could be a problem when there are grinding sounds each time you engage a certain gear or gears. This could mean a full gearbox replacement that could cost you an arm.
Suspension
Take the car to places where there are road irregularities and speed bumps. These are good places to test out the suspension of a car.
The car shouldn't have too many vertical movements like you will experience on a boat on rocky seas. If the car suffers from too much vertical movements then the dampers could have been a goner.
Steering
Take the car down a stretch of straight empty road. As you cruise down the road, set the steering wheel straight and release your hand. The car should continue to track straight and not pull over to one side. If it does, it indicates that the wheels are out of alignment.
Next perform u-turns to the right and left and check for any clicking or popping sound. The car should turn smoothly and silently. Clicking and popping noises indicates damaged Constant Velocity (CV) joints. The CV joint is attached at the end of each drive shaft. Its function is to transfer torque to the wheels as it is steered as well as to accommodate for up and down motions of the suspension. Driving with a damaged CV joint might result in you having to change the whole drive shaft, which will cost a bomb.
Professional Opinion Is The Best!
Sadly, even though the car might drive well, smell nice and look good, it does not mean that there are no underlying problems with the car.
As a precaution and peace of mind, it is strongly recommended for you to send the car in for a detailed inspection at a reputable inspection centre such as STA or Vicom. These inspection centres will put the car through a whole series of diagnostic test and reveal problems that no amount of test-driving would. They should also be able tell you if the vehicle has been through a major accident before.
A certificate of differing grades will be presented after the inspection to the car. A grade "A" indicates the car is in good condition and has not been in an accident before. A car that has been through an accident before would score a grade "C".
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