If the owner talks incessantly during the test drive, ask him/her to please not talk so you can listen to the car. Talking your ear off is a favorite trick of used car salesmen that want to divert your attention from the car's mechanical condition.

What to Look For

..1. Brakes: Apply the brakes and feel how the car stops. If your attention is called to the car pulling to the left or right, there is a problem. If you fell pulsation in the brake pedal or hear squeaking you know there is a problem that may be expensive to repair. You’ve driven cars before and know how they should feel.

..2. Drive Axles: Try turning a corner. Turn left. Turn right. Be sure to make a sharp turn from a dead stop while accelerating. If you hear a click, click, click sound from the front of the car this means the drive axes will soon need to be replaced. This is expensive.

..3. Steering: Drive in a straight line and feel how far you can turn the steering wheel before the car begins to veer. If there is lots of free play (movement) before turning the steering wheel takes effect this signals problems in the steering system. A steering box and accompanying linkage are expensive and require heavy labor to replace. Also, a car should go straight on its own and not need constant correction of the steering wheel position to keep it from veering to the left or right.

..4. Suspension: Drive over some bumps and determine if the car gingerly negotiates the bump or if it seems to thump down or bounce up and down. Either of these scenarios means suspension problems.

..5. Transmission: Accelerate from a dead stop and feel how the transmission changes gears. It should be smooth. If you are driving a manual shift be sure to see how the shifter goes into first gear while the car is stopped. Go from neutral to 1st gear while the car is not moving. Any hesitation or resistance means looming transmission problems.

..6. Clutch: Apply the parking brake. Put the car in third gear and slowly let out the clutch while pushing on the gas pedal. Apply the gas like you would when you leave a stop sign. If the motor continues to run when you let out the clutch this signals a slipping clutch that will soon need to be replaced.

..7. Extraneous Noises: Drive around and listen for strange noises, feel for hesitation on acceleration or any thing else that signals something is not normal.

Should you detect anything abnormal about the car during the test drive I would not purchase it unless you get a professional quote on the repair and deduct the price from the selling price. Problems with any of the systems I’ve had you test during the test drive can eventually leave you stranded or cause an accident to occur.

The Curbside Inspection

..1. Check the Condition of the Valves and for Oil Burning. The valves open and close to allow gas and air to enter the motor and for exhaust to exit. Burnt or sticking valves will reduce engine performance, waste gas and in short order require a major and very expensive motor repair.

Allow the motor to idle (foot off the gas), firmly apply the parking break and put the transmission in neutral. Walk around to the back of the car, grasp a dollar bill at one end and move the free end up to the exhaust pipe. The exhaust exiting the pipe should cause the dollar bill to flap back away from the pipe. If at any time the bill is sucked up against the exhaust pipe this signifies one or more of the valves in the motor are burnt, or worse. The exhaust should only flow outwards from the motor. Any reverse action reveals a major problem.

..2. Check for Smoke. While you’re at the back of the car be aware if smoke is coming out of the exhaust pipe. Exhaust is clear in color; blue smoke signifies oil is being burnt. Black smoke means the gas in the motor is not being completely combusted due to a number of problems. Have the car owner press and release the accelerator pedal a few times while you watch from the rear of the car.

..3. Check the Internal Condition of the Motor. When gas explodes inside a motor you want all the power of that explosion pushing downwards on the pistons, which in turn equates to power to the wheels. Rings seal the pistons to the cylinders and prevent the power of the exploding gas from escaping past the pistons. Burnt gasses are really exhaust and when they get past the rings and into the motor you can be sure expensive repairs are just around the corner.

Detecting if there are exhaust gasses in the motor is simple. After the test-drive park the car and let it idle. Be sure to apply the parking brake and put the transmission into neutral. Now pull out the oil dipstick (the stick used to measure how much oil is in the motor). Look carefully for smoke coming out of the hole from which you removed the dipstick. If you see smoke, this is exhaust that has gotten past the rings and pistons and into the bottom part of the motor known as the crankcase. Not only does exhaust coming from this location alert you to a worn engine it also means exhaust is contaminating the motor oil which is flowing through the entire motor and not doing its job. Parts are now wearing at a rapid rate. Don’t buy a car with this problem.

..4. Another Check of the Internal Condition of the Motor.
If you don’t see smoke coming out from where the oil dipstick was removed, put the dipstick back where it belongs and now perform another test for the some problem. With the motor running carefully unscrew the oil filler cap (where the oil is poured into the motor) and tilt it a bit to see if smoke is escaping. Don’t lift the cap all the way off as some drops of oil may fly out. Loosening the oil filler cap and looking for smoke here as a better place to look than from the dipstick tube as we did above. If you see any smoke coming out don’t buy the car.

Shut off the motor and have a look around under the hood. Look at things like nuts and bolts and wires and tubes and caps and everything visible to the eye. If you see tied-up wires, rounded bolt heads, bent metal parts, mismatched tubes, odd looking wires, things that have been hammered, and you get the feeling a 12-year old has been working under the hood, this is not the car for you.

..5. Check the tires for concealed secrets. The tires can tell you a lot. If the car has 3 or 4 different brands of tires this tells you the frame may be bent or the suspension parts are very worn. Cars generally wear out the 2 front tires at the same time and the 2 back tires at the same time. The backs may or may not wear at the same speed as the fronts but should wear out and be replaced as a set. Three different brands of tires on a car are a signal that the tires are all wearing at different rates. This is always due to either worn steering and suspension parts or a bent frame. Of course all the tires may look new because they have all been recently replaced. If the car pulled to one side or the other while driving in a straight line and the tires are new, you can conclude there is a problem with the steering or suspension system and the new tires are there to disguise it.

If the car you are buying is a front wheel drive and the front tires are worn and the backs are new, I would take this to mean that the car is eating front tires. What has happened is the fronts wore out from poor suspension or steering parts and were thrown out. The used back tires were then moved to the front to endure the same torture. When these are worn out the driver will take the backs and move them to the front and put new tires on the back, again. And so the cycle goes on and on. Also look to see if the tires, both front and back are wearing unevenly. Excessive wear on the inside or outside of the tire signifies a problem with the steering and/or suspension system.

If the car you are considering passes all the above tests I would say it’s a good purchase. At this point you should arrange to drop the car off at a shop your school recommends. A little money spent now to be sure you didn't miss something may mean big savings in the future.