Buying used cars in Nigeria: How to check the engine


Posted by: Hassana Obi

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Read our article to get a lot of helpful tips and advice to check the engine when buying used cars in Nigeria.

Buying used cars in Nigeria is a tricky business, mostly because you can't rely on the dealer to give you a good deal. The car body, transmission, and tires are parts that buyers should pay attention to. However, most attention must be given to the car engine. Though the car drives well and looks clean, there may be hidden problems with the engine.

The cost of fixing a bad engine is not cheap at all. That’s why naijauto recommends that you check the used car thoroughly before making a final decision. Whether you are doing this yourself or having a mechanic do it for you, these helpful tips will reveal the true state of the engine and maintenance over the years.

>>> You might also be interested in: Tips to protect the gearbox - the most expensive part in your car

1. Check the vehicle service records

Not all dealers have the service records which help you to know whether the car was maintained frequently or not. If you are provided with the service reports, pay attention to the car’s mileage and oil changes. This helps you to verify if the car has oil changes frequently or not. Depending on the model, the advised interval between oil changes can be between 3,750 and 10,000 miles. If the car was driven longer than the recommended interval without changing oil, its engine will wear out.

For the car that comes equipped with a timing belt, look for any service record revealing times the belts were replaced. Normally, this component should be replaced every between 60,000 and 100,000 miles, depending on the type of the car. 

How to buy a used car part 3: Used car Engine Inspection

2.  Start the car cold

The dealer will typically prepare for your insection visit by starting the car before you get there and making sure everything is running smoothly. The way to discover any issues is to arrive much earlier than when you agreed and starting the car cold. This will reveal any engine problems. Is the battery okay? How is the smoke from the exhaust? If it's blue or very black, or just too smoky, you know you have the wrong car.  

3. How does the engine sound?

Fine, this is a used car, s the engine might not be emitting the low hum of a brand new car. Having said that, you certainly don't need a rattle or clanking or even grinding noises coming from the engine. These are always sure signs of a poorly maintained engine or an outrightly bad engine.

4. Check under the hood

Always take a look at the car engine before starting a test drive. A flashlight will be useful. Ensure that the engine is off, the parking brake is on and the transmission is at "Park". If the engine parts look shiny and clean, it does not automatically indicate that they are well-maintained as the car sellers usually clean their cars’ engines before showing them to buyers. Below are some examples of what you need to look for:

4.1. Signs of sloppy maintenance

If the car you intend to buy has a battery that looks similar to this one, it may mean that the vehicle didn’t have frequent maintenance.

A dirty battery

Poor looking battery is a red flag for vehicle maintenance

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4.2. Leaks

This car’s performance is quite good but on closer inspection, you can see that the coolant is leaking. As a consequence, this car’s radiator needs to be replaced by a new one. Sometimes, a cracked radiator may even lead to other more serious issues. So, it is advisable not to buy a used car having this kind of problem.

The coolant is leaked

The coolant is leaking and this could mean more problems

>>> See more: Reasons Why You Should Not Ignore Your Car’s Engine Coolant

Also, check if the car has an oil leak. Oil leaks are not easy to spot from above but a wise trick is for you to look underneath the car with a flashlight. Inspect the transmission and the engine’s lower parts. It should be dry like this vehicle. A little wetness might be acceptable but the leaks shouldn’t be there.

oil leaks on a car

Check the car for oil leaks too

4.3. The smell of burnt oil under the hood

When you are under the hood, be alert to wrong smells. This is the engine of an Audi. It appears shiny and clean but when checked, it has a pungent smell of burnt oil, revealing potential problems.

An Audi engine

The engine has a pungent smell of burnt oil, revealing potential problems

4.4.Turn off the engine and inspect under the oil filler cap

This inspection can reveal much about the condition of the car engine. In case you are not confident with making this inspection, let your mechanic take it over. Shut down the engine, open the oil cap and take a good look at it.

the oil filler cap

Shut down the engine, open the oil filler cap and take a look at it

Here is an example for you. In the left photo, there's a thick layer of black carbon accumulated under the oil filler cap. The oil cap and the parts inside the engine are also very dirty. Normally, it is a clear sign of infrequent maintenance. The photo on the right shows a good and clean oil cap.

Dirty and clean oil cap

The right photo shows a good and clean oil cap

4.5. Oil level is low

As checking this car, we realized that its oil level is very low and the oil also looks not clean. This discloses that this engine drinks oil or the latest time the oil of this car was changed was very long ago. Additionally, the engine will be worn faster if the oil is low. Typically, the oil level should be not too much lower than "Full" mark.

oil level

The engine will be worn faster if the oil level is low

On the other hand, this car shows clean engine oil and its oil level is acceptable, which means the car oil has been changed lately.

oil level

The oil level is acceptable

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4.6. Look for performance modifications

If a used car shows some modifications to enhance or improve its performance, pay close attention to it. If done properly, modifications do increase the car’s performance a lot. However, if the adjustments are not done well, it could bring the car a lot of problems, especially if the original parts of the car are not available. If the vehicle has got some modifications, chances are it has been put in races or suffered other strenuous use.

a car engine

If a used car shows some performance mods, pay more attention to it

5. “Check Engine” light remains on

Once the car has started, all of its warning lights on the dashboard should be off. For instance, in this vehicle, the “Check Engine” remained after the car started which indicated some faults in the engine. The problems could be either minor or consequential and cost much money to fix. It is hard to tell by eye so you'd better walk away. 


The “Check Engine” is still on after the car’s start, that's bad

>>> You might also want to know: 10 common reasons why your car won't start & how to fix it

6. Smoke from the exhaust

Look at the photo, you can see that this car generates a blue-gray smoke from its exhaust when running. And when doing the check, there was smell like burning oil. And the blue smoke shows that oil is being burned by the engine. Don't buy this car.

blue smoke in a car

The blue smoke shows that the car engine burns oil

6. Test drive

Of course, you need to do a test drive. You should look out for vibrations, engine noises or any other driving problems. When the engine starts, it should run smoothly without delaying or shaking. When you press the acceleration, the engine shouldn’t buck or stumble. If it does, there is an issue. It should be stable at idle as well. Your test drive should last as long as possible because sometimes, problems don't show up on a short drive. It is suggested to drive the vehicle in all modes and conditions: deceleration, acceleration, highway cruising, and stop-and-go traffic.

Also, take a look at the temperature of the engine showing on the dashboard. As soon as the car engine is warmed up, the temperature gauge should be around the middle of the scale.

Even if every part of the car looks good, we still advise you to have a professional look at it before purchasing.

>>> More tips and advice for inspecting used cars:

>>> Naijauto keeps you informed with car buying tips that work

Hassana Obi

Hassana Obi

Car prices

Hassana Obi is an automobile writer and editor at She prides herself on hundreds of informative and entertaining articles on Nigerian traffic regulations, car prices and celebrity car collections. When Hassana is not writing, she is a teacher and philanthropist.

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