5 Important Tips for Checking a Used Car Before Buying


So, after careful consideration, you’ve decided to buy a used a car. Congratulations! Now comes the most important part of the process – inspecting it.

Today, we will look at the most essential tips when checking a used car. One of them involves using an OBD scan tool to get the best value for your money. So buckle up as we take this ride.

First of all, buying a used car is a great way to sort out your mobility concerns without paying the hefty price that comes with a new car. However, if you’re not keen during inspection you may end up paying significantly more for maintenance. That’s one thing you want to avoid by all means.

Also, keep in mind that used cars depreciate faster than new ones. The best way to have a decent resale value is to buy a decent car in the first place. And that’s where proper checking comes into play.

Unfortunately, a vast majority of car buyers have little to no knowledge about the things to check when inspecting a used car. Here’s a five pointer read to give you an advantage over the seller.

Pull vehicle information

Here you want to see the car’s ID, history and mileage. Vehicle ID is basically a VIN (vehicle identification number). It’s a unique code (usually 17 characters) that acts as the car’s fingerprint.

You can use the VIN to check engine code, recalls, thefts, warranty claims, maintenance records and the entire history of the car. With this information you’ll know whether the car is stolen, if its legally available for sale, if it has been involved in accidents, and the number of times that important parts (like engine) have been replaced. A car that has had a long history of maintenance should cost less than one with fewer visits to the shop.

How do you pull this information using the VIN? There are two ways. First, you can run the VIN through a paid service.

The second option is using an OBD scan tool to view VIN and vehicle info. Most scanners provide this information automatically when you plug them in the car’s OBD port. It’s an easier and straightforward option than using a paid service.

Once you have all that data, you can go ahead and check the vehicle’s mileage. On average, a car will clock 12,500 miles per year (20,000 km). Multiply that with the car’s age and you’ll get a rough idea of its mileage.

If you want a more precise figure, take the odometer reading and divide it by the car’s age. This is a more reliable method because not every motorist racks up 12,500 miles per year. Some do more while others do less. Needless to say, a high mileage means more wear and tear.

Pay attention to tire condition

You can tell a lot about a car just by looking at the condition of its tires. More specifically, observe tire tread to see if there’s uneven wear. Usually, when one or few tires wear faster than the rest, it means that the car is poorly aligned.

The same goes for uneven tread in a tire. That too may be an indication of poor alignment, which is itself a symptom a bigger issue relating to the suspension, steering or frame. When you drive such a car you’ll notice that it tends to pull to the side.

Another reason why you have to inspect tires is that they may need immediate replacement. New tires are quite expensive and can set you back a lot, especially if you have to buy the entire set. Make sure the final price takes this factor into account. And as you inspect the tires, be sure to check the trunk if it has a spare.

Inspect the interiors and exteriors

More often than not, a seller will slap a new coat of paint on a car and then do some waxing to make it look neat. In reality, the car may have a few dents and leaks here and there. Those are usually signs of further trouble either in the engine or any other essential system.

Walk around the car to look for paint damage and rust. A small rusty patch shouldn’t be a bummer. But if you spot a large metal that’s totally rusted, you should be more concerned.

It indicates either an accident or a poorly maintained car. Either way, you’ll most likely spend a good amount on maintenance soon after the purchase.

After the walk-around, open the car and check its upholstery. Is the fabric in good condition? Are there cracks, tears and stains? If yes, you may have to budget for new upholstery, and it can be very pricey.

Next, sit in the car and check its interior electronics and accessories. Roll the windows up and down. Switch the A/C on and off. Turn on the radio, blast some tunes and then turn it off.

You can worry less if all those systems are in perfect working condition. Now, if you want to be 100% sure that no electronic system is faulty, you can use an OBD scan tool to check for errors. The best OBDII Scan Tools can check the climate control system (includes A/C), body control module and other systems that house electronics. 

Check the chassis and under the hood

Naturally, you’ll want pop the hood of the car to see what its working with under there. Make sure the engine is turned off and then visually inspect hoses for leaks. Check if belts have any cracks or if they are extremely worn out.

You don’t want to buy a car whose belts are on the verge of breaking. In addition to taking time out to visit the shop, you will spend some money ($200 or more) to fix each broken belt. It will be more expensive if it’s the serpentine belt.

Engine leaks, on the other hand, usually point to a much bigger problem. It could be a faulty oil pan, loose valve cover, loose plug or worn out seals and gaskets. If the leakage is green, then it’s probably the coolant. Oil leakages are usually yellowish red.

Regardless, a prolonged engine leak can damage the entire engine and force you to replace it altogether. The problem with a used car is that there’s no way of telling how long its engine has been leaking for. To be on the safe side, avoid buying any car with an engine leak.

Now proceed to check the chassis. Observe whether the car is sitting level on flat ground. If not, chances are it has frame issues and might have been in accident recently.

If you can raise the car, then do it. Check if the exhaust system has cracks or soot deposits. The latter (soot) typically indicates that there’s a problem in the internal combustion engine.

The same goes for black smoke or excessive white smoke. Under normal circumstances, exhaust smoke should be thin white. If its blue or gray, it means there’s an oil leak. Black smoke means the engine is not burning fuel efficiently while excessively white smoke means a leaky head gasket.

Use a scan tool to check for faults

Visual inspection of a car is great, but it can only tell you so much. For example, you can’t know that the exhaust system is getting excess oxygen just by looking at it. In case you’re wondering, excess oxygen in the exhaust is not a good thing.

You would need an OBD scan tool to diagnose that. Plug it in the car’s OBD2 port and it will throw a code P0171 with the description “system too lean”. That’s a fancy way of saying that there’s excess oxygen in the exhaust.

Just like that, you will have pinpointed an issue that you otherwise wouldn’t have known. The best part is, a reliable OBD scanner will check every system in the car and tell you if there are any faults.

That’s why it’s very important that you have one of these devices with you when buying a used car. If the car was made before 1996, you will need an OBD1 scanner to inspect it. On the other hand, if the car is a 1996 or newer model, you will need an OBD2 scanner.