Buying a used car may seem easier than buying a new car (no additional taxes and insurance premiums) and makes the transaction smoother. However, consumers will slowly discover that, apart from the price, there are inevitably some other troubles. These things are often frustrating. Here are some of the common ones.

1. Scratches on the exterior

A one-or-two-year-old vehicle will still look as good as new, but it is inevitable that there are some minor scratches. The most economical way for those who like to DIY is to buy a bottle of special paint in the same color as the car body and get it done. It won't cost too much. If you choose to have your car repaired in the repair shop, it can be a little expensive.

2. Interior renovation

Some used cars generally don't have much room for improvement in the interior, mainly in the form of scratches or wear in areas of high use, such as the gearshift knob, where a simple waxing is all that is needed.

If car owners want to do it themselves, it's easy. Common car wax can be used multiple times. If possible, the steam disinfection of the interior helps. If you want, you can replace the original carpet to keep it clean.

3. Carframe

The carframe is an important part to check. It may be deformed by the impact. There will be uneven and unstable steering, automatic wheel deflection when going straight, tyre deflection and severe wear on the front suspension, etc. Do not be careless.

Check the upper and lower crossbeams at the front of the engine, the two secondary beams inside above the wings and the two longitudinal beams below the engine. Check if these areas are flat and remain as they are.

If the screws have been disassembled, the original welds are deformed, uneven, or have been burnished and shaped, the area has suffered severe deformation.

Despite being repaired, the parts associated with these areas can be abnormal. Some of the vehicle's performance can be affected.

4. Luggage

Open and close the luggage compartment to see if it is flexible and if the seals are intact. Take the carpet away to see if the floor is rusted and if there are traces of welding and spray paint. The flatness of the floor edges and the colour of the paint can tell whether a rear-end accident has occurred.

If the luggage compartment has had a weld shaping, it is an indication that the rear end was more severe and may have caused a poor seal or even a leak.

5. Electric equipment

All ancillary equipment, such as wipers, horn, stereo, instruments and various lights, must be dynamically checked and confirmed to be intact and working properly.

Check whether the various switches are flexible and available, whether the air-conditioning is good, whether the seat adjustment device is effective, whether the window glass lift is smooth, whether the sunroof switch is normal, whether the seat belt is practical, etc.

6. Fuel System cleaning

Fuel system cleaning is also an essential item for new owners of used cars. Changing new engine oil, brake fluid and automatic transmission fluid can improve the engine power performance and extend the service life of the components.

Choosing synthetic motor oil over mineral oil is more effective in the cleaning process. Some products can also play a role in removing carbon. Synthetic motor oil is not expensive.

It is best to seek help from a professional mechanic to clean engine carbon. He will use a professional oil circuit cleaning fluid to complete the process. The principle is to put the cleaning fluid into the throttle door instead of fuel.

When the engine is working, the cleaning fluid flows through the various parts, cleaning the oil injection and cylinders. Used cars that running for three or four years need more attention for oil filter and fuel filter cleaning and replacement.

7. Short circuit

Some simple electrical problems can be spotted when driving a used car, but a thorough electrical check is also necessary as you don't know the previous owner's driving habit.

There are two main types of car circuits: low-voltage and high-voltage. Check the interfaces of the components of the low-voltage circuit to see if the wires are burnt or have poor contact. We should also pay attention to the condition of the fuses.

On the other hand, the battery has a service life of about two years. It is a vital component. The price of a typical battery for a 5-seat small car has different prices according to different brands.

Car owners should not check the high voltage circuit alone. It is best to ask someone to do it at a repair shop. If the vehicle has been running for more than 20000-40000 km, it is recommended to replace the spark plugs to get better engine performance from the original car.

8. Spark plug

The ignition component sends a high voltage current into the cylinder to produce spark to ignite the combustible mixture.

The electrodes are consumed by spark discharge from where they are prone to discharge. In particular, the central electrode is consumed by acidification as it reaches higher temperatures.

The spark plugs need to be replaced only once when the car has been driven for more than 30,000 km. If you do not know how long the spark plugs of the car you just bought have not been changed, you can first remove them for inspection and see if they need to be replaced.

9. Air filter

Air filters reduce the amount of pollutants entering the vehicle through the heating, ventilation and air conditioning system. They prevent the inhalation of contaminants that are harmful to the vehicle. Air filters are primarily responsible for removing particulate impurities from the air.

The condition of the air filter is related to the engine's service life. If a dirty air filter is used when the car is running, it causes the engine to have insufficient air intake and incomplete fuel combustion, resulting in unstable engine work, reduced power and increased fuel consumption.

Some old used cars are with air filters that have not been replaced for a long time. It is advisable to check the actual condition and replace them as appropriate.

10. Deodorisation and disinfection

It is an essential procedure for deodorising and disinfecting the interior of a used car. In addition to the usual cleaning and dusting, owners are advised to have a deep-cleaning interior sauna (incidentally, you can check the air conditioning filter) at a repair shop if available.

Pay attention to the details of the car's interior, including the seats, body panels, glass, etc. If you have cleaned the car, roll up the windows and let the car air out for a while.

After closing the door, put in bamboo charcoal and other items that can eliminate odors to increase the deodorising effect.

11. Transmission components

For used cars that are over three years old, the timing belt is an important part to maintain, and many owners overlook this. And once the timing belt is misaligned or broken, it can easily cause improper engine combustion and severe damage to other components.

Therefore, owners who find that their vehicles are rattling while driving must check the timing belt and replace a set of timing belt equipment.

If you bought a used car with a manual gearbox model, you also need to check the wear of the clutch plates. After a certain number of years of running, uneven wear can cause the clutch plates to slip and reduce their effectiveness.

When you find that the clutch is not working properly, it is best to adjust the clutch plate. If the situation still does not improve, you need to consider replacing it.

12. Tyre wear

The frequency of tyre replacement is relatively low among the components but cannot be ignored for used cars. A used car that doesn't run for long generally has relatively new tyres from the surface and will not be too badly worn.

After purchasing a car, it is advisable to have a four-wheel alignment and check the tire pressure condition. Some used cars that didn't have their tyres replaced will have significant wear. At this point, the new owner should replace the original tyres at the first opportunity.

13. Brake pads

For used cars with more than 50000 kilometers, it is essential to check the working condition of the brake pads and replace a set of them.

14. Other driving habits

After buying a used car, owners also have to adjust the car handbrake height, clutch height, steering slack and other things to suit their size and driving habits for just a few dollars.

In short, when selecting a used car, we must be careful and check all the parts we can. After knowing how to check as mentioned above and being observant, we can definitely buy used cars that you are satisfied with.