The principle of operation of a diesel engine.
Buying a used car is always risky. An external inspection can only detect damage to the body, but it will not determine the degree of wear and tear of internal parts or show how much the fluids have exhausted their life.
First of all, it is necessary to carry out a comprehensive diagnosis of the car during the first maintenance. In this article, we’ll take a closer look at what to look for and what parts to replace when buying a used car.
Visually, the car may look perfect – the paint is shiny, there are no scratches or rust, but there may be problems with the insides, because it is far from certain that the previous owner consciously carried out maintenance on time and regularly. And since it is difficult to check the maintenance history, it is recommended that you take a comprehensive approach to maintenance. At the first MOT, it is recommended to carry out a number of mandatory procedures that will allow you to use your newly purchased car for a long time and reliably. Here is a list of the technical components of the car that need to be diagnosed and replaced if necessary:
- Battery and generator (battery condition and ability to charge);
- Electrical equipment (door locks, windows, wipers);
- Auto lights (headlights, hazard lights, brake lights and turn signals);
- Ignition system (spark plugs, injectors, valves);
- Braking system (levers, brake fluid, brake pads and discs);
- Transmission (condition of lubrication, integrity of the unit);
- Engine and radiator (filters, oils, antifreeze, etc.);
- Suspension and chassis (shock absorbers, wheels, tyres, etc.);
- Interior and body (paintwork, upholstery, car covers, etc.).
Let’s take a closer look at all of these procedures that you have to deal with when diagnosing and restoring a car.
Replacing the battery
Most batteries can operate normally for up to 5 years. But 5 years is more likely the maximum battery life, not the average. Therefore, it is imperative that you first check the date of manufacture of the installed battery and if more than 3 years have passed since the date of manufacture, you should consider buying a new one. The issue of replacing the battery before winter frosts becomes especially relevant, because in the cold season, the old battery can fail at the most inopportune moment.
Changing the coolant
The engine gets very hot during operation and must not be allowed to overheat. When the engine reaches the end of its service life, the mixture of antifreeze and water turns into an electrolyte, which can corrode metal components. If the engine operates at very high loads and, accordingly, gets very hot, and the cooling system elements rust, the cylinder head gaskets may burn out, the cylinder blocks may deform, and the oil seals will leak oil.
According to the regulations, the cooling system must be serviced every 3 years. Coolant is extremely important for the normal and long-term operation of the vehicle engine. Before replacing the coolant, flush the entire cooling system and dispose of the old coolant. Special equipment is required for this purpose and it is recommended to leave this process to experts. After the cooling system has been cleaned and before the new coolant is added, all hoses should be checked and those that are most severely worn should be replaced.
Changing the brake fluid
Brake fluids are hygroscopic, meaning that they can absorb moisture, but they also thicken and have less resistance to heat and corrosion. It is recommended that the brake system be serviced every few years, but many used car dealers may not perform additional service before selling a car. It is important to replace the brake fluid with fresh fluid, as old fluid may have a lower boiling point, which in turn can lead to overheating of the calipers and a general decrease in braking performance.
Changing the engine oil
Engine oil is vital for your vehicle’s engine. At the first service, it is recommended that the oil filter is completely replaced and new engine oil is added. A new oil filter and fresh oil can reduce fuel consumption and improve engine starting. In addition, it will be possible to keep a clean record of routine maintenance and observe the correct oil change interval in the future.
Engine oil should be selected in accordance with the recommendations of the vehicle manufacturer. It is extremely important to pay attention to the oil tolerances specified in the documentation.
Changing the transmission fluid
Transmission fluid is a power converter for servicing the gearbox, clutch and drive wheels. Cleanliness of the transmission fluid is extremely important in hydromechanical transmissions. The transmission fluid should be changed if foam forms on its surface or there is a burnt smell. This indicates that the power unit is overheating.
The first fluid change should be made after 10,000 km, and subsequent changes should be made every 50,000 km. For manual transmissions, the first change is also required after 10,000 km, and subsequent changes are required every 80,000 km. To ensure optimum service life of your vehicle’s powertrain, we recommend following these tips.
Replacing the filters
In an older car, 4 filters can be replaced: air, oil, fuel and cabin filters.
The air filter prevents debris and dust from entering the engine, thereby extending its life cycle. Optimal flow of clean air is essential for efficient fuel combustion.
A new oil filter will get rid of dirt and various impurities.
It is recommended to clean the fuel filter regularly and change it if necessary, as it affects the service life of the fuel system and fuel consumption.
The cabin filter is used to clean the air that enters the cabin from the outside. If the filter is dirty, exhaust gases and polluted air can enter the cabin. To protect yourself from the negative effects of pollution, it is recommended that you regularly clean or replace the cabin filter.