What You Should Look for When Buying a Used Car

In the market for a used car? You’re not alone. Somewhere around 40 million pre-owned vehicles trade hands each year. Used vehicles can be diamonds in the rough, nightmares on wheels, or something in between. Knowing what to look for when buying a used car can go a long way toward understanding a car’s condition, and help you make a smart purchase decision. 

Whether you’re buying from a dealership or a private party, here’s our comprehensive guide on what you should look for the next time you’re shopping for a used car. You can also refer to our handy used car inspection checklist for easy reference while you’re car shopping.

Look for Accident Damage

We get it - everybody gets in a fender-bender now and then. But that doesn’t mean you want a previous owner’s poorly repaired car that previously doubled as a battering ram. Luckily, there are 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, or structural ripple effects from the accident. But the end result will be the same: 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 such as Autocheck. You can learn about the differences between Autocheck Vs. CARFAX with our handy guide.

So how do you obtain a vehicle history report? Used car listings on iSeeCars.com include a free VIN check, which often links to a free CARFAX or Autocheck report when provided by the dealer. Otherwise, a CARFAX report costs $39.99 for a single report, but can be cheaper if you purchase multiple reports at once, while an Autocheck report costs $24.99. 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 while browsing the used car lot after scanning the vehicle’s VIN barcode.

Ask for Service Records

Along with a vehicle history report, ask about service records as well. Many fastidious owners keep receipts of all the maintenance records for services they may have performed on the car. This is the best way to ascertain what sort of mechanical condition the car is in.

Some service history may be found on a vehicle history report, but these reports typically only include work that was performed by a dealership and not by an independent mechanic. 

Inspect the Tires 

Another thing to look out for 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.

Evaluate the Interior

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.

Beware of Water Damage

Water damaged cars from a flood or even as a result of leaving windows or the sunroof open can pose a significant safety risk because water corrodes mechanical parts and can hinder important safety features like airbags and antilock brakes. While water damage may not be immediately obvious during a visual inspection, there are telltale signs if you know what to look for.

Along with a visual interior inspection, you should also perform an inspection with your nose. If the inside smells moist or like mildew, it could mean that there is water damage or leaks. Also beware of excessive car deodorizer, which can be an attempt to mask the smell. 

Another indicator is new interior fabric or upholstery that is in far better condition than the rest of the vehicle. If the interior was replaced, the chances are good that water damage may have been the culprit. Be sure to pull back carpeting and look under floor mats for signs of staining.

Lastly, inspect vehicle lights to see if there are any visible water lines or if they appear foggy.  

Check for Rust

Rust under the car can be another indicator of water damage, but it can also appear if a car was regularly exposed to harsh weather. Rust can be a sign of serious bodywork issues down the line. Rust negatively impacts the price of the car and most often appears around the wheel wells, at fastening points (wherever screws or bolts go through the panels), and underneath the vehicle at frame mounting points and around fasteners and connection points on the chassis.

Visually inspect for rust as best you can. 

A professional mechanic should look more closely if the car passes your initial inspection. On a car’s body, rust is repairable but can be expensive if you aren’t a do-it-yourself bodywork expert. Rust on the working parts of an automobile can be a sign of serious issues coming soon, and it's a good reason to pass on the vehicle's purchase.

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, transmission 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, or on the dipstick in the case of engine oil. 

Like the oil, the transmission fluid has its own dipstick (on automatic transmission models). Trans fluid can vary in color, but it's usually red or green. It should be clean and at the correct level, according to the dipstick marks. More importantly, it should not smell burnt or metallic. Transmission fluid with questionable quality (dirty, of mixed color) or smelling burnt is reason to believe that expensive transmission problems are coming. The transmission dipstick is located under the hood in the engine compartment. It’s typically clearly marked with a transmission symbol or with a specific color.

It’s rare when power steering or brake fluid is low or dry, but coolant is a bit more fickle. Coolant keeps the engine operating at the right temperature. 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. When the engine is cool, you can remove the cap and look at the fluid in the radiator. Vehicles equipped with an overflow can have that fluid inspected as well, but nothing beats looking at the fluid that’s actually circulating in the car. It should be a uniform color that’s clean and oil-free. Dirty coolant is not a reason to walk away from a purchase, but coolant that's contaminated could indicate other problems, which can be worrisome.

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 confirm 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.