1. There is air in the hot water tank of the car: there is air in the water tank of JAC Ruifeng s3, which causes the water tank to knock when the car is started, and it needs professional technicians to check and maintain it.
2. Coolant circulating in the car: When the engine temperature of JAC Ruifeng s3 rises, the coolant circulates in the car, and the coolant will also become hot, which will lead to the knocking of the water tank. It is necessary to adjust the circulation path of the coolant or replace it with a more suitable coolant.