Buying a used car shouldn't be as easy as 1, 2, 3. There are a few important details you should check. The most important being the car's engine! While it may be a bit complicated to most people, there are a few things you should be able to check by yourself.

In this article, we will take you through what to look out for in an engine of a used car. We will help you understand its components and their importance.

If your engine doesn't run, your car won't start

An engine consists of these main parts:

  • Engine block: houses most engine parts such as cylinders, camshaft, pistons, and crankshaft.

  • Cylinder head: This hosts the components that enable intake and outtake of air and gases. These are camshafts and valves.

  • Crankshaft: turns the movement of pistons into the needed circular motion.

  • Connecting rods: Enables collaboration between the crankshaft and the pistons.

  • Pistons: By their motion, pistons provide energy to the crankshaft. Piston rings reduce friction in the cylinder.

  • Spark plugs: These enable combustion by providing the spark that ignites incoming air and fuel.

  • Fuel injectors: They provide the engine with fuel.

  • Valves: There are two types; intake valves allow gas and air into the engine, while the exhaust valves release the exhaust.

  • Camshaft: It enables the opening and closing of valves.

  • Timing belt: It helps make sure the camshaft and crankshaft are in sync.

There are some types of car engines. The difference in those is mainly in the arrangement of cylinders. They include:

  1. Inline engines - cylinders in this are in a straight manner.

  2. V-style engines – The cylinders in this are separated into two groups and end up forming a V-shape.

Other types are tuned according to the power or efficiency the owner/manufacturer wants to achieve.

What to Check Old Car Engine before Buying

Now you got general knowledge about a car engine.

After checking the interior and exterior conditions of the car, one more important step you should take next is to check its engine. Below are what you should check for:

2.1 Check Service History and Maintenance Record

Checking the service records of the vehicle is one of the most crucial steps to take!

You get to learn about the health of the engine and any potential worrying signs from this. If you can get your hands on service records, you will know if the car undergoes regular maintenance. Details to look for are those on oil changes and mileage. Depending on the car's manufacturer, an oil change should be between 3,750 to 10,000 miles. You should be concerned if the intervals are irregular.

If the vehicle has traveled longer than the period of an expected oil change, internal damage could occur, or the motor could be affected. Also, check to see if there have been changes to the timing belt (if available).

2.2 Check the noise of the engine

To check this, cold start the car. If the engine was already warm, it could hide some noises. Keep your ear out for any unusual noise, e.g., thudding sounds or heavy clunking. Normal clicking sounds are okay as they will disappear once the car hits up.

If you notice unusual noises, it is better to leave the car or seek the advice of your trusted mechanic.

2.3 Inspect Under the Hood

To do this, make sure that the engine is off, the handbrake is engaged, and your vehicle is in Park mode. Once done, open the hood and look for traces of any leakage, funny irregular smells, signs of bad maintenance, or lack of, and any enhancements that have been done.

When a used car is on sale, the sellers try to have everything as clean as possible! Don't let this trick you into thinking all are okay.

Check under the hood is an important step to check used car engine.

Look for the following:

  • Check the quality of oil and its level

Use a dipstick to check the oil level. If it's low, it either means it has been a while since the last oil change or that the engine consumes oil. An engine with low oil wears faster. If that's the case, avoid buying the car.

Also, take note of the color of the oil. The expected color is either yellow or brown. Any other color should be a red flag! If the oil looks like mud, avoid that car as oil hasn't been replaced in a long time.

  • Look for leaks

Oil leaks may not be visible when you open the hood of the car. Because of this, you have to kneel and check from the bottom. To be sure that the engine has no leaks, it has to be completely dry.

  • Beware of smoke

Perform this test while accelerating.

For diesel cars, a bit of black-shaded smoke is okay. For a petrol car, however, any sign of smoke from the engine is a bad sign:

  • White-colored smoke: the engine has blown a gasket.

  • Dark-colored smoke: the engine burns a lot of fuel.

  • Blue smoke shows that the car excessively burns motor oil.

2.4 Cold start the car

Cold starting is the best way to identify most engine problems. Make sure that the engine has not run in a while. If the battery is aging, it may not start and may need boosting.

Be on the lookout for any peculiar noise or smoke emitted by the engine. If any of this is evident, it may mean you need to look for another vehicle.

2.5 Take a test drive

Even after taking all other mentioned steps, take the used car for a spin. When you start the car, check to see if the check engine light will stay on. If it does, you can use an OBDII scanner to diagnose the issue. It is advisable to get a scan tool specifically made for the car brand you're buying. For example, if you're testing a Ford vehicle, you should go for an accredited Ford scan tool.

Check for any signs of irregular noise from the engine or smoke, especially if it's a petrol car.

Final Words

Buying a used car is a cheaper option than a new one. But if you buy one with a bad engine, this could end up being too costly for you. With constant engine repairs, you may end up having to buy a new one. As such, be sure to use the steps above to verify the engine's health before buying that used car.