7 "problems" that weaken a car engine.

1. Worn spark plug electrodes

For perfect combustion, the spark plug must produce a strong spark at the right time, ensuring maximum combustion pressure when the piston is at top dead center. Worn spark plugs, large electrode gaps, and inefficient combustion of the air-fuel mixture reduce power output. Adjusting the gap should be done according to the specific recommendations for each vehicle model.

2. The air filter is too dirty.

This is the reason why insufficient oxygen in the combustion chamber weakens the engine, especially for vehicles that frequently travel in dusty environments. You should clean the air filter every 3 to 6 months and replace it regularly according to the manufacturer's instructions.

3. Clogged fuel filter

This is considered the most common cause of engine weakness, and it can even lead to the engine stalling in the middle of the road. However, if this happens on the road, you can stop the car for a while and then restart it to continue driving. Additionally, you should have your car's fuel filter replaced regularly at a reputable auto repair shop because it's very difficult to do at home.

4. Clogged drain pipe

Catalytic converters help reduce the amount of toxic gases released into the environment. However, over time, they can become a factor in exhaust gas buildup. Exhaust gases accumulate in the pipes, requiring the engine to expend more energy to push them out. High exhaust pressure also reduces intake air volume, leading to power loss.

5. Worn fuel pump or leaking pressure regulator.

The ECU controls the fuel supply based on the injector's opening and closing timing. Fuel pressure in the system is maintained stably between 2.0 and 5.8 atm thanks to the continuously operating fuel pump and regulator. Low pressure reduces the amount of fuel supplied to the combustion chamber.

Fuel pumps are very durable, with an average lifespan of up to 6 years, and are often replaced unnecessarily. When replacing the fuel filter, if the injection pressure remains low, some garages often attribute the problem to a faulty pump and decide to replace it. In reality, many cases are due to a leaking or clogged pressure regulator, preventing the fuel from returning to the tank with sufficient pressure.

The injection pressure is adequate, but the amount of fuel entering the combustion chamber may still be lower than required. This is because the mass air flow (MAF) sensor or the mass air pressure (MAP) sensor reacts slowly, transmitting incorrect signals, causing the ECU to control the injector opening time to be too short.

6. Low compression ratio

This problem commonly occurs in vehicles with infrequent oil changes or those that have been in use for many years. During the combustion and expansion stroke, high-pressure gases leak through the gap between the piston and cylinder or between the valve and its seat, eliminating the compression pressure on the piston.

In severe cases, oil can enter the combustion chamber, fouling the spark plugs. Engine oil also gets dirty faster. This is a serious malfunction requiring a major overhaul. To accurately identify the problem, you can check by pumping compressed air into the combustion chamber through the spark plug port and measuring the pressure drop during the compression stroke (all valves of the air distribution system are closed).

7. The car has had infrequent oil changes and is old.

Vehicles that have had infrequent oil changes and are old may experience low compression ratios, leading to engine seizure and reduced power. This problem could indicate serious damage to the vehicle, so you should promptly take it to a reputable garage for inspection and repair.