Signs of problems to watch out for when test driving a used car

January 24, 2020

Before driving, make sure the car has a license plate(s) and insurance. Safety first! Adjust the seat and mirrors and get familiar with controls. Don't drive if the vehicle feels unsafe, request to correct all the problems before the test drive. The longer you drive, the more chances you can catch signs of problems. Often problems become more evident once the vehicle is fully warmed up.

Car smokes

Avoid the car if you notice smoke from the exhaust.

For example, an automatic transmission may start acting up or the engine may show signs of overheating only after 20-30 minutes of driving.

Some issues (e.g. noisy wheel bearings, drivetrain vibration, alignment issues, noisy tires are more noticeable when driving on the highway. The suspension and steering noises are easier to notice when driving slowly over rough roads. It's difficult to test an all-wheel drive system and all of its features in normal driving conditions. If the vehicle has all-wheel drive, ask a mechanic to test all of its features during the pre-purchase inspection. What to watch out for during a test drive:

With the car standing still:

Does the engine turn over and start easily? Does it run smoothly? Watch out for odd noises.
When shifting from Park to Drive or from Park to Reverse, does the transmission engage right away, or is there a long delay? Avoid the car if there is a long delay or if the transmission engages with a strong jolt.
When shifting between Drive and Reverse, do you feel a strong jolt or a clunk? Avoid the car as it indicates possible transmission or driveline issues.
Does the brake pedal go too far down to the floor? Does it feel spongy? Does the brake pedal feel too hard, like there is no brake assist? Avoid the car if yes.

Does the hand brake hold the car from rolling on an incline?
Do you feel excessive engine vibration inside when the car idles in Drive? This may indicate that one of the engine mounts is bad and needs to be checked.

In city driving:

Does the engine feel smooth and responsive or sluggish? Do you notice a hesitation on acceleration? When stopped at a red light, is the engine idling smoothly or are the rpms jumping up and down?

Engine overheats

Avoid the car if the engine overheats.

Does the engine have enough passing power? For a turbocharged engine, watch out for smoke, hesitation or abnormal noises on acceleration or excessive turbo lag.

For vehicles with an automatic or CVT transmission: Do you notice shuddering, jerkiness, or loss of power during gradual acceleration? Do rpms fluctuate up and down when driving at a steady speed? Does the transmission shift harshly or with a delay? Do you feel a jolt when coming to a stop? Does the car shudder when accelerating from a stop? Avoid the car if you notice any of these symptoms as they might indicate possible transmission or driveline issues.

Another common sign of automatic transmission problems is slipping. It's noticeable when you press the gas to accelerate after coasting, the engine rpms increase but the vehicle speed remains the same, as if the transmission is in Neutral. Often a worn transmission engages with a jerk or shudder when accelerating after coasting.

For cars with a manual transmission: Try accelerating and decelerating in every gear. Watch out for grinding or abnormal noises when shifting in and out of any gear. A worn-out transmission may pop out of gear. A vibration felt in the clutch pedal, or odd noises when the clutch pedal is depressed or released, indicate a problem.

The clutch is the key component that must be tested. If the clutch only starts engaging when the clutch pedal is released almost all the way, the clutch might be worn.

Warning light

Warning lights indicate problems; some could be expensive to repair.

Slipping on acceleration in 2-nd, 3-rd or 4-th gears or a burnt clutch smell are also signs of a worn-out clutch. Normally, the clutch should engage somewhere in the middle of the pedal travel and there should be no slipping or jerkiness in any gear. Jerkiness when releasing the clutch often indicates oil contamination of the clutch disk. Transmission and clutch repairs are expensive.

Do you notice any humming or whining or other abnormal noises or vibrations when accelerating or decelerating? This may indicate possible issues with transmission, AWD system, driveline, wheel bearings etc. A clicking or popping noise when accelerating in turns might be caused by bad CV-joints.
In an all-wheel drive vehicle: vibration or judder from the rear of the vehicle when making slow turns on dry roads could be caused by a problem with the rear differential or AWD coupling.

Does the car struggle to hold a straight line or pulls to one side? Is the steering wheel off-center when driving straight? The wheel alignment must be checked.
Knocking, thumping or rattling noises when driving on rough roads indicate possible suspension or steering issues.
Does the car continue to bounce up and down after driving over a bump? Shock absorbers or struts could be bad. Does the vehicle lean too much in turns? The sway bar hardware must be checked.
Does the car pull aside during braking? Do you feel vibration or abnormal noises when braking? This indicates a possible problem with brakes.

On the highway:

Take the vehicle on the highway only if it's safe. The vibration may indicate an issue with tires, rims or driveline. Watch out for excessive wind noise. A humming noise can be caused by a bad wheel bearing, noisy transmission or driveshaft bearing, cupped tires or other issues. Does the car feel stable and secure or is it hard to control and "wanders" side to side? Warped or rusted brake rotors may cause a vibration or shake felt in the steering wheel when braking or exiting the highway.

After the test drive:

Warning lights on the dash, overheating, lack of heat from the vents or smoke from the exhaust are also the reasons to avoid the car. If you don't feel comfortable, look for another car, there are so many used cars available on the market. If you are not sure whether it's a problem or a normal occurrence for this vehicle, consider test driving another car of the same make and model to compare.