Common faults of Mercedes-Benz cars are:
1. Four-wheel positioning
Symptoms: after the four wheel positioning value is out of alignment, the vehicle will feel the direction is heavy when turning, and the correction is not good, and the tire will appear eccentric wear phenomenon. According to the maintenance statistics, when a car with Mercedes-Benz W140 chassis travels about 60,000 to 70,000 kilometers, the positioning value is often out of alignment due to the damage of the lower suspension rubber sleeve.
Solution: when the above fault occurs, it is necessary to change the suspension rubber sleeve to the repair shop in time and adjust the four-wheel positioning.
2, replace the spark plug
Symptoms: after the performance of the spark plug becomes worse, when you are driving, you will feel the lack of engine power, the rapid acceleration of the car and the exhaust pipe with a "sudden, sudden" sound, the engine jitter when idling and other phenomena.
Solution: It is recommended that you check the spark plug at the repair shop every 30,000 km and replace it if necessary.
3, free of disassembly cleaning injector
Symptoms: after the nozzle is dirty, the engine will have difficulty in starting, power decline, slow acceleration, shivering at idle speed, black smoke, exhaust exceeding the standard, and the engine will not be able to start in serious case.
Solution: do not remove cleaning nozzle, cleaning at the same time can also be the combustion chamber and the top of the piston carbon cleaning off. It is recommended that vehicles be cleaned every 20,000 km. This can also avoid the intake system carbon accumulation is too thick.
4. Oil leakage of steering engine
Symptoms: After the repair kit of the car steering machine on W140 chassis is damaged, there will be a lot of oil stains on the outside of the steering machine, causing loss of steering booster oil. Serious oil loss in the steering will make a lot of noise, if not timely repair will make pump oil loss damage.
Solution: If oil leakage of steering machine is found, the steering machine repair kit should be replaced in the repair shop in time to prevent the damage of components caused by oil loss of steering power system. Generally, when a car with W140 chassis travels about 100,000 kilometers, there are more oil leaks in the steering engine.
5. The water pump is damaged and leaking coolant
Symptoms: W140 car water pump leakage coolant phenomenon is more common. When the pump is damaged, the coolant will leak. When the coolant loss is serious, the coolant temperature will be too high and the engine will be damaged.
Solution: found that the water pump has leakage of coolant phenomenon should be replaced in time, so as not to cause greater loss.
6, the fuel pump failure phenomenon
Symptoms: The fuel pump pressurizes the fuel to the injector. General Mercedes Benz W140 chassis car fuel pump before damage will issue "squeak, squeak" sound, when the fuel pump is damaged, the fuel can not be injected into the engine, the engine will stop working.
Solution: when the fuel pump abnormal sound, should be replaced in time, so as not to break down the car.
7. Failure caused by damage of brake switch
Symptoms: The car equipped with ASR system in W140 will light up the ASR light after the brake switch is damaged, and sometimes it cannot accelerate when driving.
Solution: When the ASR lamp is lit, it should be checked by diagnostic instrument in the repair shop. Generally, the brake switch causes the ASR lamp to light up more.
8, the air flow meter fault phenomenon
Symptoms: A car with an ME injection system has an engine whose air intake is measured by a hot film air flow meter. Air flow meters are particularly vulnerable to damage due to their structure. After the damage, the vehicle appears weak acceleration, black smoke, unable to run to the highest speed, no idle speed and other phenomena.
Solution: It is suggested to clean or replace the air filter in time according to the driving air condition. Only by keeping the dust content of the air entering the engine regularly can the life of the air flow meter be prolonged.