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Secondhand cars: Which parts to check before purchasing?

Second hand cars

Never buy a used car without inspecting it yourself, even if it’s not brand new. Remember, you’re spending your hard-earned money here. Take your time and be super careful checking every part.

Keep an eye out for warning signs such as mismatched tires, engine block fillers, questionable touch-ups, uneven paint, and parts that don’t work. Additionally, don’t forget to inspect these three crucial auto parts thoroughly. 


When inspecting a used car, always look at its underbody or underside, the lower part of the car that sits closest to the road. It’s where important car components are and can give a lot of clues about the car’s history. 

Specifically, the underbody can show how well the car was taken care of, where it usually stayed, the weather it faced, and any damage it might have gotten. For example, big dents in structural components located on the floor or fuel tank may mean the car crashed before. 

Another concern is that car issues, such as rust, bent components, or improper repairs, can be easily covered with subtle undercoating. However, this doesn’t mean they won’t cause any issues in the future. That’s why it’s important to check every part carefully.

If you can go under the car, you can do a basic check-up. Just make sure the car is raised and safe. Use a flashlight to look for red flags, like red or green liquid on the ground or in the engine, oily drips, and signs of wear on the pipes and muffler.

If you’re unsure what to inspect, leave it to the professionals. Ask the car seller whether they can provide a service lift to the nearest car repair or maintenance center. If not, ask someone knowledgeable about cars or hire a mechanic to give you professional advice before purchasing. 

If you’ve chosen a car with a few issues, take note of them. They may likely influence your car insurance, so take time to research them or, better, directly bring them to your insurance providers. 

While in contact with your insurer, don’t forget to ask other questions related to car insurance that you’re confused about. For example, does car insurance cover scratches, or is car insurance mandatory in your area? Don’t hesitate to ask. After all, it’s part of their customer service, so take advantage of it. 


You can also get relevant information about the used car just by looking at their tires. Their treads, in particular, can tell how the car will run. For example, the following are different tire tread wear and what causes them.

  1. Center Rib Wear – If the center part of a tire is excessively worn, it’s called center rib wear. This often happens when the tires are overinflated. Too much air pressure makes the inner wall of the tires stiffer, reducing the contact patch. This can seriously affect the ride’s comfort and safety.
  2. Flat Spot Wear – If you notice flat spots on the tires, it shows brake issues. This is very unsafe, so taking the car to a repair shop is highly advised.
  3. Side/Both Shoulder Wear – Damages on the sides or both shoulders of the tire are often caused by underinflation. This can break brake lines, rotors, calipers, suspension systems, and chassis. Underinflated tires can also cause the vehicle to handle poorly. 
  4. Cupped/Scalloped Tire – If there are patchy sections on the tires that look like scallops with a diameter of around 3-4 inches, they’re cupped. Poor-quality tire construction, tire imbalance, wheel alignment issues, or car shock absorbers and suspension problems can cause this.


The engine is like the heart of a car, and even in a used one, it should be in top shape. One of the things to keep an eye on is the engine fluids. Specifically, watch out for any liquids, especially oil, around the engine or on the ground under it. This could indicate issues like loose wires or corroded batteries. 

Additionally, check what the fluids look like. They say a lot about a car’s condition. Take the engine oil as an example. It should be black or brown without residue. If it’s honey-colored, it has likely been changed recently. 

Another example is transmission fluid. Normally, it should be pink. If it’s brown and smells burnt (usually around the center of your vehicle or near the gear shifter while driving), it indicates that it’s already old and needs to be changed. 

Check the coolant, too. It’s a liquid of antifreeze and water, ensuring the car engine doesn’t overheat and gives you a smooth ride. It should be orange or green, not milky or rusty. 

The same goes for the radiator. Like coolant, it’s a key component of the cooling system in the engine. It’s mainly responsible for eliminating excess heat from the engine. One of the telltale signs that it’s broken is when you see a greenish gunk on it. 

This green stain, sometimes bright yellow or red, may come from leaking coolant. A common cause for it is corroded radiator tubes. If the coolant is the leak source, it’s a huge problem. As mentioned, coolant plays a big role in lowering a car engine’s temperature. If it leaks, the engine may overheat faster, compromise performance, and pose a health hazard. 

However, it’s still possible that the leak source could be caused by something else, such as a hose or the radiator itself. Just to be sure, request for a pressure test. This helps determine where the leak source is. 

Final thoughts 

A second hand car’s underbody, tires, and engines are just among the many components you should thoroughly inspect. If unsure, always seek professional help. Additionally, always conduct a test drive to observe how the car performs on the road. Taking these steps ensures a more informed decision and helps you avoid potential issues down the road.