How to Inspect a Used Car Before Making a Purchase

In the market for a used car? You’re not alone. Used cars are big business: somewhere around 40 million pre-owned vehicles trade hands each year. That’s a lot of secondhand cars - and not all are the low mileage garage queens their sellers might make them out to be. Used vehicles can be diamonds in the rough or nightmares on wheels, but knowing what to look for can go a long way in ensuring you avoid the lemons and bring home a cherry.  Here’s our comprehensive guide on what to watch for the next time you’re checking out a used car:

Look for Accident Damage

We get it - everybody gets in a fender-bender now and then. No one’s perfect, right? But that doesn’t mean you want someone’s shoddily repaired car that briefly doubled as a battering ram. Luckily, there’s a few telltale signs of accident repair that can be easy to spot if you know what to look for.  The quality of the paint job is the first thing to inspect, and is usually the easiest way to determine whether a car has been in some sort of collision. Look first to see if the coloring on one body panel is different in shading or tone than the rest of the car. If a fender looks lighter or darker than the rest of the car, there’s very good odds it was repainted at some point or another. Panel gaps can also be suggestive of accident repair. The average auto body shop likely won’t reassemble a damaged car to the exacting standards of the factory. This can be for a number of reasons: ill-fitting aftermarket parts, employee skill levels and time constraints, structural ripple effects from the accident. But the end result will be non-uniform panel gaps. Look particularly close at the four corners of the car as well as the front and rear fascias - all common places for an accident to occur. Run your hand along the small gaps between the panels. Does it widen or narrow considerably? Is there anywhere you can stick your finger between two body panels? Do panels improperly align when they come to a junction? If a car hasn’t been altered from the factory, the answer to all the above questions should be no. If you find a car where this isn’t the case, return to the classifieds and keep looking. Any suspicions of prior accident damage can often be confirmed by getting a vehicle history report. These comprehensive reports use the vehicle identification number (commonly referred to as the VIN) and should disclose any incidents that would have triggered insurance involvement. CARFAX is the best known purveyor of vehicle reports, but there’s plenty of other options as well. When browsing the listings on, be sure to look at a car’s VIN report , which will often link to a free CARFAX report when provided by the dealer. Otherwise, a CARFAX report costs $29.99 for a single report, but can be cheaper if you purchase multiple reports at once. . The VIN report will also provide you with important information about the car to complement the CARFAX report such as listing history, pricing analysis, and projected depreciation. The report can also be accessed via the iSeeCars VIN Report app, available for iOS and Android , which allows users to instantly view the comprehensive report after scanning the vehicle’s VIN barcode.

Inspect the Tires and Interior

After you’ve taken a good look at the paint job and body, inspect the tires. You ideally want to see four matching tires. If it’s wearing multiple different kinds of tires, the different tread designs and asynchronous treadwear mean handling will be compromised, as will inclement-weather performance. A car drives best when equipped with one type of tire all the way around.  Another thing with tires is tread depth. Tires wear out as you drive on them. As they wear, the tread recedes. Keep running them long enough and you’ll eventually get bald tires - the term for tires that have no tread left. And when there’s no tread, there’s nothing gripping the road, which can be a severe safety hazard. Be sure to inspect the tires for good tread depth. Inside, evaluate the interior. Inspect stitching, door pulls, and the lower plastics on the doors for scuffs, looseness, and general wear. Take a look at the upholstery for excessive cracks and tears. Make sure all the electrical features work - mirrors, windows, reading lamps, and whatever other gadgets the car might be equipped with. Run the air conditioning and make sure it’s cold, and do the same with the heat to verify it’s warm.  Double check that the odometer readout is what the salesman or private seller is claiming. There shouldn’t be any shenanigans with actual tampering - that old trick of shady used car dealers isn’t quite as easy to do nowadays, what with the digital readouts found in modern cars - but you want to make sure the dealership isn’t trying to bait you into looking at a car with more mileage than they may have initially claimed.  Remember that some wear is guaranteed; unless you’ve stumbled on a used car worthy to be a museum specimen, expect to find imperfections. But there’s no need to buy a car that shows signs of excessive wear and tear when there’s plenty of other options out there. Find a car that looks like it was treated in the same manner that you intend to treat it.

Delve Under the Hood

It might not be so important when buying a new car, but when you’re shopping for a used car it’s critical you pop the hood and take a look at the engine. Even if you don’t know an air filter from an air balloon, there’s some universal red flags to keep an eye out for - and if you can spot them you’ll be saving yourself from unwanted expense and heartache. The easiest place to start is with the fluid levels in all the reservoirs. When you’re poking around the engine bay you’ll see power steering fluid, brake fluid, windshield washer fluid, and coolant. It’s no big deal if the wiper fluid is looking low, but all the others should read between the designated full/add marks clearly labeled on each reservoir.  It’s rare when power steering or brake fluid is low or dry, but coolant is a bit more fickle. Some cars have been known to have coolant issues if the head gasket - an important bit of rubber that ensures a snug fit between the engine block and the cylinder head - begins to deteriorate. This is a common malady in old Subarus, for instance. If you don’t want a potential four-figure repair bill be sure to inspect the coolant.  It’s also important to inspect the condition of the coolant, not just how much is in the tank. Unlike the other fluids, coolant has a relatively short shelf life and should be changed regularly according to the interval in the owner’s manual. Neglecting this can cause trouble down the road. Be sure to look at the coolant and if it’s a light, slightly opaque color. It should not look dark, muddy, or thick. That’s a serious sign of potential trouble. Be sure to also look at the condition of belts and hoses. These are rubber pieces; over time they become brittle and dry, especially with the temperature swings that regularly occur under the hood. You want these parts to have a little bit of give when you prod them with a finger, and you don’t want to see any cracks. Don’t be afraid to pull the dipstick and double-check the oil. Good oil has a golden brown color and it should be within the hashes, holes, or crosshatches that all might mark the acceptable range of oil. If you get a dry dipstick, oil that looks milky-white, or a dipstick encased in sludge, don’t walk away - run.  And an easy thing to forget but certainly worth doing is looking under the car for leaks. If you see any puddles that aren’t water from the air conditioning system, move on. Besides a visual inspection, ask about service records as well. Many fastidious owners keep receipts of all the maintenance they may have performed on the car. This is the best way to ascertain what sort of mechanical condition the car is in.

Take the Test Drive

So you’ve done a thorough walk-around and the car looks good. Now it’s on to the most important aspect of the used-car buying process: the test drive. It’s tempting to blast the radio and roll the windows down as if you’ve already signed the paperwork, but the test drive process needs to be approached more judiciously if you’re to learn whether the car is hiding any ugly secrets. To that end, there are a few good strategies to use that will help sniff out any trouble lurking behind a pretty paint job. The first thing you want to do is start the car with the windows up and the climate control and radio turned off. Listen to the idle and look at the tachometer. Is the car idling smooth? Did it start right away? Are they any noises that seem suspect? Unless it’s very cold out, a good car will turn over quickly and promptly settle into an even idle, indicated by the tachometer needle hovering consistently at an appropriate increment. Once it’s idling without issue, double check the instrument cluster for any illuminated warning lights. You don’t want to see any lights on the dash other than the indicators for things like lights and drive modes.  Now get on the road. If the location allows for it you’ll want to drive on a mix of roads, from twisty narrow streets to the straight and open interstates. See how the car handles and reacts at various speeds and conditions. You’ll want to make note of any strange noises or erratic behaviors. Check the transmission shifts fine through all gears, that features such as cylinder deactivation and start-stop are working properly, and that the brakes work well at various intensities, from a gentle slowing to a true panic stop. A mix of road conditions is also important. If the suspension is halfway decent, the ride will be fine on smooth roads not speckled with cracks, frost heaves, potholes, or sewer caps. The real test happens on the ugly roads, the ones pockmarked with the ravages of old age and temperature swings. Driving over rough pavement will clearly expose any suspension issues. Specifically, listen for a loud banging over bumps - that could be bad shocks or struts failing to dampen the impact. Vibrations at certain speeds - felt through either the seat or steering wheel - could be indicative of steering, alignment, or wheel bearing issues. If the steering wheel pulls in one direction or feels loose there could be issues with alignment or some of the steering components.  Pull into an empty parking lot and do some tight figure eights to further evaluate the condition of the steering and suspension systems. Even with the steering wheel cranked all the way to one side there shouldn’t be any noises or thumps - everything should function normally. Be sure to go full lock on the steering wheel in both directions. Even if it is a used car, you still expect it to handle nimbly, brake confidently, accelerate strong, shift well, and give a good ride. A thorough test drive across as many conditions on as many different roads can offer insight into all these factors. It might sound like a lot to look for, but such an evaluation shouldn’t take more than thirty minutes or so.  Remember to do all this with the windows up, the radio silenced, and the climate control off or otherwise programmed for a low, unobtrusive setting. You want to hear nothing but the car itself.

Play with the Radio

This used to be a quick thing - turn it on, browse the FM, hear a few stations come in clear, turn it off. However, late-model cars are running far more advanced systems than radios of even ten years ago. Infotainment software has become nearly as complex as a computer or smartphone, and it should be evaluated as such. This is doubly true if you’re buying a late-model luxury car. Spend time to cycle through the infotainment menus. Find the features that are important to you - how easy is it to connect your smartphone? Does it respond to commands quickly or is there a lag time? Are there redundant physical controls for common inputs, like radio tuning and volume? Is it overall an intuitive system to use? That last question is crucial to your own long-term satisfaction. Remember, you’ll be driving this car every day; the last thing you want is to be cursing the system every time you try to switch from FM to the aux cord.  Automakers have taken different approaches to their software, so if you’re not focused on one or two particular models be sure to try a few cars out and see which system suits you best. Some might hate the Mercedes system that uses a large dial in the center console but love the haptic Chrysler Uconnect system. Others might feel the opposite.  With infotainment being such a critical and highly variable aspect of today’s cars, don’t discount the importance of spending a few minutes to learn the system that’s used in your potential next car.

Final Thoughts

Buying a used car can be a daunting prospect. It is, after all, one of the most expensive things you’ll ever buy. But if you’re armed with the right information and do your due diligence, there’s no reason to feel pressured or intimidated by an enthusiastic salesman or pushy car dealership. Read - and reread - all the points listed above. Be smart and objective. And most of all be ready to walk away if you see anything that raises your eyebrows.  If everything checks out, gain further peace of mind by having a trusted mechanic conduct a pre-purchase inspection on any car you’re tempted to pull the trigger on. Paying a professional $50 or $100 to mechanically look over your potential purchase might save you from bringing home a costly money pit. Keep all this advice handy the next time you’re car shopping and you’ll be driving home the perfect new-to-you used car in no time at all. Are you on the hunt for a used car? Begin your search with the iSeeCars used car search engine , which features 59 user-friendly search filters to help you find the right car at the best price. And when you’ve found your car, you can run an iSeeCars VIN check report to answer all the important questions to make sure your used car purchase is a smart one .