Expert Tips on How to Inspect a Used Car

Whether you are talking to a private seller or a used-car dealer, ask these questions over the phone or over email. The answers can help you decide whether the vehicle is worth the trip to inspect.

How many miles does it have? If the total mileage averages more than 20,000 per year or lower than 5,000, ask why. A high-mileage car used on a long highway commute may actually have less wear than a car that did a lot of short trips with stop-and-go driving. Still, be somewhat skeptical of any “these were all highway miles” claims. Also, while low mileage is nice, it’s no guarantee of gentle care.

How is it equipped? Whether they’re listed in the ad or not, ask about key features: transmission type, safety equipment, audio system, cruise control, power seats, Bluetooth, rear entertainment screens, backup camera, and navigation. Double-checking to confirm the listing can also tell you how honest the seller is being with the listing.

What’s the car’s condition? After you ask this intentionally broad question, don’t interrupt. The seller may bring up something you wouldn’t have thought to ask about.

How is the body and interior? If the seller didn’t address this already, ask specifically about both.

Has it been in a crash? If it has, ask about the extent of the damage, the cost of repairs, and who did the work. Don’t worry about minor scrapes, but think twice about a car that has been in a serious collision. Verify the seller’s answer with a vehicle history report, such as from Carfax.

Do you have service records? An organized pile of repair and maintenance documents usually indicates that a car has been cared for. Look up the maintenance schedule for the specific make and model of car you’re considering, and ask for copies of the car’s service records. Then, check to make sure the previous owners followed the manufacturer-specified service intervals. Also, ask for receipts for any parts that have been replaced. Receipts from repair shops normally note the odometer reading, helping you verify the history.

Are there open recalls? Ask whether any safety-recall work needs to be done. Dealerships can access the recall history, but with the VIN, you can check the manufacturer’s website or the National Highway Traffic Safety Administration website. Note the mileage when work was performed. To learn more, check CR’s Car Recall Tracker.

Have you owned it since it was new? You want to be able to piece together the car’s service history. Be skeptical if the owner claims to have done the maintenance but can’t produce any receipts, or if the car has changed hands multiple times in a few years. A vehicle history report from a service like Carfax can help explain this history.

Are you the person who drove it the most? Ideally, you want to meet the car’s principal driver or drivers. If you get a sense that they’re responsible, that’s another good sign.

Why are you selling the car? Look for a plausible explanation rather than an interesting story. If the answer sounds evasive, be wary.

The Federal Trade Commission requires car dealers to post a Buyers Guide in every used vehicle offered for sale. Usually attached to a window, it must contain certain information, including whether the vehicle is being sold “as is” or with a warranty, and what percentage of repair costs (if any) the dealer is obligated to pay. The information in that guide overrides any contrary provisions in your sales contract. In other words, if the guide says that the vehicle is covered by a warranty, the dealer must honor that warranty. If any changes in coverage are negotiated, the guide must be altered to reflect them before the sale.

If a sale is designated “as is,” it means the dealer makes no guarantees about the condition of the vehicle. Any problems that arise after you have made the purchase will be your responsibility. However, many states do not allow as-is sales on vehicles selling for more than a certain price. Check the seller’s state’s policy and see whether it applies to your potential purchase.

When you go to check the car, dress in clothes that you don’t mind getting dirty. No matter whom you buy from, always look over the vehicle thoroughly. Be prepared to get on the ground and handle dirty components. You should also bring thin gloves, a rag or paper towels, and a flashlight to help when checking fluids and looking beneath the vehicle.

Plan your inspection to happen in daylight on a dry day—floodlights and rain can make cars look shiny and hide body defects. Ask the seller to park the car on a level surface, and to have them abstain from driving it for at least an hour before your inspection. These conditions will make it easier for you to spot any issues.

Finally, before you go to inspect the car, find a mechanic nearby who can do a pre-purchase inspection (PPI). Having a professional check for potential issues with expensive parts is always worth the $100 to $150.

Body condition: Check each panel and the roof, looking for scratches, dents, and rust. Watch out for misaligned panels or large gaps, which can indicate either sloppy assembly at the factory or shoddy repair work. The paint color and finish should be the same on every body panel.

If you think the body or other parts of the car have been repainted, check for paint on the rubber seals around the hood and trunk lid. 

Rust is always a cause for concern, so check the body for blistered paint or visible rust. Check the wheel wells and panels, especially beneath the doors, and door bottoms. 

Open and close each door, the hood, and the trunk. Gently lift and let go of each door, particularly the driver’s door. If it seems loose on its hinges and won’t stay in place, the car likely hasn’t been used delicately. Inspect the rubber seals around each door for tearing or rot.

Glass: Look carefully at the glass to make sure there are no cracks or large, pocked areas. A small stone chip might not be cause for alarm, though you should bring it up in negotiations. But any crack in the windshield or other glass will worsen and lead to a costly repair.

Suspension: Walk around the car to see whether it’s sitting level. Then use your body weight to push down on each corner. If the shock absorbers are in good shape, the car should rebound just once before settling. If the car bounces up and down, it has suspension issues. Also, grab the top of each front tire and tug it back and forth. If you feel play in it or hear a clunking sound, the wheel bearings or suspension joints may be shot and require repair.

Lights and lenses: While in the driver’s seat, have a friend standing outside confirm that all lights are working—high beams, low beams, turn signals, and brake lights. Walk around the outside to make sure that all light lenses and reflectors are intact and not cracked, fogged with moisture, or missing. 

Tires: You can tell a lot about a car—and its owner—from the tires. A car with less than 20,000 miles, for example, should probably still have its original tires. Be wary of a low-mileage car with new tires. Also, check to make sure all four tires are the same. If there are different branded tires on the car, ask why they have been replaced.

Treadwear—how much the rubber has worn down—should be even across the width of the tread, and the same on the tires on the left and right sides of the car. Ask whether the tires have been regularly rotated. If not, in a front- or rear-wheel drive car, the wheels that get power will usually have more wear. 

If tires are more worn down on the outside edges, near the sidewall, that may indicate that the car has been driven aggressively. That can be okay, but consider it as a factor in the car’s overall history.

Tires that have been driven while overinflated tend to wear more in the middle than on the sides. Chronically underinflated tires will show more wear on the sides. "Cupped" tires—uneven wear marks across the tread—may be a sign of a larger problem with the steering, suspension, or brakes.

Tires must have at least 1/16 inch of tread to be legal on the road. Check the tread depth with a tread-depth tool—available at auto parts stores—or a quarter. Insert the quarter into the tread groove, with Washington’s head down. If you can see the top of his head, the tire should be replaced.

Examine the tire sidewalls for scuffing, cracks, or bulges. Also, look for dents or cracks on each wheel. Check to make sure the spare is in good shape, too, and that the proper jack and lug wrench are present. (Learn more in our tire buying guide.)

Odor: When you first open the car door, sniff the interior. A musty, moldy, or mildewy smell could indicate water leaks. Remove the floor mats and check for wet spots on the carpet. An acrid smell may indicate that the car was used by a smoker. Check the lighter and ashtray (if so equipped) for evidence. Some odors, such as mold and smoke, can be very hard to get rid of.

Seats: Sit in every seat. Upholstery shouldn’t be ripped or badly worn, particularly in a car with low mileage. Try all the seat adjustments to make sure that they work properly, and that you can find a good driving position.

Don’t forget about the back seats and, if applicable, the third-row seat. Even if you won’t be sitting there regularly, try out each seating position to look for lumps in the padding or uneven support. If the seats can be folded down, make sure the lowering mechanism works. If it’s a three-row SUV or minivan, make sure the second-row seats can smoothly tilt or slide out of the way.

Pedals: The rubber on the brake pedal, clutch pedal, and gas pedal indicate how the car has been used. A car with low miles shouldn’t show much wear. Pedal rubber that’s worn through in spots—or brand-new—can indicate that the car has been driven a lot.

Instruments and controls: Turn on the ignition switch without starting the engine. Make sure all the warning lights—including the check-engine light—illuminate for a few seconds. When you start the engine, all of the lights should turn off. Note whether the engine is hard to start, and listen and feel whether it feels smooth at idle.

Then, try every switch, button, and lever. With the engine running, turn on the heater full blast to see how hot it gets, and how quickly. Then, switch on the air conditioning and make sure it quickly blows cold.

Sound system: Check reception on AM, FM, and, if the account is active, the satellite radio. If the car is old enough to have a CD player, try loading and ejecting a disc. Pair your smartphone via Bluetooth or plug it in. If the car has wired or wireless Android Auto or Apple CarPlay, pair your phone to make sure the system works.

Some older vehicles may have software compatibility issues connecting to newer phones. Check online for any potential issues, and ask the seller if there are software updates to address the problem.

Roof: Check the headliner and roof trim for stains or sags to see whether water is leaking through ill-fitting doors or windows. If the vehicle has a sunroof or moonroof, make sure it opens and closes properly and seals well when shut. Inspect a convertible top for tears by shining a smartphone or flashlight up into it.

Trunk: Use your nose as well as your eyes. Sniff and look for signs of water entry. See whether the carpeting feels wet or smells musty, and check the spare tire well for water or rust.

Wait until the engine is cool. Ideally, the car hasn’t been driven for at least an hour. First, inspect the general condition of the engine bay. Dirt and dust are normal, but be wary if you see oil splattered about or on the pavement below. Also, be on the lookout for a battery covered with corrosion, or wires and hoses hanging loose.

Hoses and belts: Squeeze the various rubber hoses running to the radiator, AC, and other parts. The rubber should be firm and supple—not rock-hard, cracked, or mushy. Feel the drive belts to determine whether they are frayed. 

Fluids: Check the owner’s manual for the section on fluids, which will point out where each reservoir should be filled to. Find and remove the oil dipstick first. Engine oil could be dark or light colored, but it should not be gritty. If the dipstick has water droplets on it or shows gray or foamy oil, it could indicate a cracked engine block or blown head gasket, two serious problems. 

When you finish checking the oil, turn the car on and let it warm up. Then, check the automatic transmission fluid with the engine warmed up and running. With some vehicles, the dipstick has two sets of marks for checking when the engine is cold or warm. 

Transmission fluid should be pinkish, not brown, and smell like oil, with no burnt odor. The dipstick shouldn’t leave visible metal particles on a rag, another sign of a more serious problem. 

Power steering and brake fluids should be within the safe zone—between the notches indicated on the reservoir. 

Radiator: Look into the plastic reservoir connected by a rubber hose to the radiator. The coolant should be greenish or orange, not milky or rusty. Greenish stains on the outside of the radiator are a sure sign of leaks.

Battery: Some “maintenance-free” batteries have a built-in charge indicator: Green usually means the battery is in good shape, and yellow or black usually means it’s dying. However, these indicate the condition of just one cell and might not accurately reflect the health of the whole battery. 

It’s unlikely that you’ll encounter a battery that requires maintenance such as filling it with distilled water. But if the battery has filler caps, wipe off the top with a rag, then carefully pry off or unscrew the caps to look at the liquid level. A low level may mean that the battery has been working too hard.

If you end up purchasing the car, you should have a mechanic or someone at an auto parts store check out the charging system and perform a “load test” on the battery. This is particularly important if its been two years since the battery has been checked. If the battery is approaching four or five years old you’re going to need to replace it

Electric vehicles and hybrids: Before any test drive, make sure that the battery has been fully charged so you can observe its projected range. For hybrids, check the in-car display to ensure that the battery is charging and discharging while you drive.

If you can find where the vehicle is usually parked, look for marks from old puddles of gasoline, oil, coolant, or transmission fluid. Clear water that drips from under the car on a hot day is probably just water condensed from the air conditioner.

Tailpipe: Feel inside the pipe for residue. If it’s black and greasy, it means burnt oil. Tailpipe smudge should be dry and dark gray. Though some rust is normal, heavy rust could mean the vehicle needs a new exhaust system. 

Underneath: If the vehicle is high enough to slide under, you may be able to do some basic checks. Spread an old blanket on the ground and look under the engine with a flashlight. If you see oil drips, oily leaks, or green or red fluid on the engine or the pavement beneath the car, it’s not a good sign. 

Look for the round, black-rubber bellows at the ends of the axle shafts that connect the wheels—these are the constant-velocity-joint boots. If these are split and leaking grease, assume that the car has bad CV joints, another costly repair.

Structural components, like the floor pan or fuel tank, with kinks and large dents usually indicate a past accident. Welding on the frame suggests that a section might have been replaced or cut out to perform repair work. Fresh undercoating may hide recent structural repairs.

If the car passes your own inspection, before you close the deal, plan to have the car scrutinized by a repair shop. A dealer should have no problem lending you the car to have it inspected as long as you leave identification. If a salesperson tells you that an independent inspection is not necessary because the dealership has already done it, insist on having your mechanic look at it. If a private seller is reluctant to let you drive the car to a shop, offer to follow the seller to the inspection shop. 

A thorough diagnosis should cost around $100 to $150, but check the price in advance. Ask the mechanic for a written report detailing the car’s condition, noting any problems found and the cost to repair them. You can then use the report when you begin to negotiate with the seller.

If you don’t know of any repair shops, you can ask a local auto parts store for the name of a good shop. If you can’t get referrals, look for a nationwide used car inspection service, such as SGS or Carchex, or at the Car Care Council, an organization supported by the auto aftermarket industry. Note that there are no performance criteria for shops listed on the site.

Research the companies on the Better Business Bureau’s website to check for complaints about any shops you are considering using. Members of the American Automobile Association (AAA) can use one of its recommended facilities.

If you’re going to a shop for the first time, look for certificates or window decals from AAA or the National Institute for Automotive Service Excellence (ASE). AAA-certified garages must meet certain quality standards. The ASE grants certificates to mechanics who pass exams in any of eight areas of expertise. The ASE does not certify shops as a whole, but if 75 percent of the employees are ASE-certified, the shop can carry the seal.

• CR’s Used Car Buying Guide
• Best Used Cars: 10 Top Picks
• Which Brands Make the Best Used Cars?
• Best High-Mileage Used Cars 
• Best Used Cars Under $20,000 for Teens
• Car Brands Ranked by Maintenance and Repair 
• How to Finance a Used Car
• CR’s Used Car Marketplace