Auto.com logo

Find your perfect car.

What to Look for When Buying a Used Car

Posted by Charlie Maniates | Mar 19, 2019

We recommend having any used car inspected by a professional mechanic before purchase. The cost, usually around $100, is worthwhile – but you don’t want to pay it many times. You can thoroughly inspect any used car you’re interested in buying to rule out the more obvious problem cases, and you don’t need to be Sherlock Holmes to avoid being swindled. With careful research, mindfulness and common sense, you can confidently assess whether a used vehicle is in a poor condition; we have some tips to help ease the process.

Examine the Exterior

When you first see the car, do a 360-degree walkaround. Closely look for superficial blemishes on the body and glass, like dents, cracks, scratches or rust, and pay attention to whether the paint color is uniform on each body panel. Additionally, be sure that the hood, doors and trunk (or liftgate) are properly aligned with the body of the vehicle.

If the vehicle is supposed to have non-aluminum metallic body panels, try placing a pliable refrigerator magnet on each panel. If the magnet doesn’t stick to a certain area, that panel may have been repaired with a nonmetallic filler, such as fiberglass. If an entire panel is nonmagnetic, chances are it’s aluminum or composite; body filler is used to repair, not to replace, entire pieces of sheet metal.

Check the Undercarriage and Tires

If you’re content with the vehicle’s exterior, move on to the underbody. Shine a flashlight and be aware of any rust in the wheel wells, floor pans, frame rails and exhaust system. Take note of any apparent leaks, as well.

Next, shift your focus to the tires, which can be very telling about how a used car has been handled. Check the tread of the tires to see if they’ll need to be replaced soon and ensure that each tire has the same amount of tread. If there are any discrepancies, find out why – it could be that a previous tire blew out, which is reasonable, or something of greater concern like the wheels being misaligned or evidence that the car was in an accident.

Also, see how the tire tread compares to the vehicle’s mileage. If the tires need to be replaced but the mileage is low, it's possible the odometer is incorrect. If the mileage is low but all the tires are new, the original tires may have blown, been upgraded or were replaced due to an accident. Ask the dealer or seller for context if you notice either of these as well.

Get Under the Hood

When the engine is off and cool, open the hood and investigate the engine compartment. Be on the lookout for rust, leaks, loose hoses and wires, corrosion near the battery or any components or covers that appear to be missing. Don’t be afraid to ask about something that doesn’t quite look right.

You should also check the fluids, hoses and belts. Make sure that the oil isn’t too dark and gritty, the coolant is clean, and that both the oil and coolant levels are correct. Clean fluids are no guarantee that the car has been well-kept, but dirty ones can prove that it hasn’t been. Squeeze hoses to find out if the rubber is firm but flexible. And feel the drive belts for any cracks or signs of wear.

Assess the Interior

After you’ve made your rounds outside the car, it’s time to evaluate the interior. As you get in the car, use your nose to scope out any bad smells such as cigarette smoke or mildew, which could be a sign of water leaking into the car. To the same end, if all the windows were open when you arrived, ask why. Then, observe the seats, carpet and ceiling to see how intact and clean the upholstery looks.

Start the car and see if any warning lights pop up on the instrument panel. Test every switch, button and control to find out if electric-powered features like the lights, wipers, air conditioning, heating, windows, sunroof, seat adjusters, mirror adjusters and sound system are working properly. Give the vents a good sniff while you’re at it. If the car has a touchscreen, test each feature within it, such as a rearview camera or GPS navigation.

Get a sense of the seats, comfort and outward visibility before you go for a drive; you’ll have plenty to pay attention to once in motion.

Take a Test Drive

Obviously, you shouldn’t buy a car without driving it first. As you accelerate, brake, handle and steer the car, remember any off-putting feelings you experience or sounds you hear. Make sure the car tracks straight when accelerating, coasting and braking. Pulling to one side or the other could indicate a misalignment or brake problem. Throughout the drive, test the functionality of features like cruise control, blind spot warning indicators, parking sensors and dashboard gauges.

Once the test drive is over, pop the hood again and see if everything looks like it did previously. Try to spot any red flags like odors, leaks or smoke.

Consult a Trusted Mechanic to Perform an Inspection

If your inspection went well, you should still have a trusted expert perform a more in-depth inspection so you can be certain about the used vehicle’s condition. A dealer or seller shouldn’t have a problem lending the car to you for this purpose, but, if they do, it could be a sign that they’re hiding something. Even if they’re not, an inspection can reveal problems the seller didn’t know and will give you an idea of how soon routine maintenance might be needed and what it will cost. Don't feel obligated to go through with a purchase if you aren’t able to get it inspected – buying a car, even if it’s used, is a major investment that requires complete confidence.