Note:
- If the vehicle has been parked on a slope for an extended period of time, the amount of oil in the hydraulic lifters will decrease and air may enter the high pressure chamber of the hydraulic lifters.
- If the car has not been used for a long time, the oil may also leak out of the oil channels, so some time is needed to fill the cavities of the hydraulic compensators and remove air from them.
- If any of the above situations occur, extraneous noise can be eliminated by removing air from the hydraulic lifters.
1. Check the oil level in the engine crankcase and its quality, replace or add the required amount if necessary.
Note:
- If there is not enough oil in the engine crankcase, air can enter the oil passages through the oil intake.
- If there is more oil in the crankcase than normal, the oil in the crankcase foams and a large amount of air is mixed into the oil.
- As the oil ages, the air stirred into the oil cannot be easily separated from it, and its amount in the oil constantly increases.
- If, due to one of the above reasons, there is a large amount of air in the oil and it enters the high-pressure chamber of the hydraulic compensator, the air inside the hydraulic compensator is compressed when the valve opens and the hydraulic compensator is also compressed, resulting in abnormal noise when the valve closes. That is, the same thing happens when too large a thermal clearance is mistakenly set in the valve mechanism drive. If you remove air from the cavities of the hydraulic compensators, their operation is restored.
The text of the article was obtained from the website www.mitsubishiman.ru
2. Let the engine idle for 1-3 minutes to allow it to warm up.
3. Without putting any load on the engine, perform the engine acceleration and deceleration procedure shown in the figure several times until the abnormal noise disappears (usually the noise disappears after 10-30 cycles, but if the noise does not disappear even after 30 cycles, then the reason is not the presence of air in the hydraulic compensators).
4. After the noise disappears, repeat this acceleration-braking procedure about 5 more times.
5. Let the engine idle for another 1-3 minutes to make sure there is no abnormal noise.