What is the reason for water backflow when the engine water temperature is not high?

[VonIvan]

The reasons for water backflow when the engine water temperature is not high are: 1. The cylinder head is uneven, and the tightening torque of the cylinder head bolts is insufficient; 2. The bolts have extended and deformed, failing to compress the cylinder gasket; 3. There are sand holes in the water passages adjacent to the combustion chamber in the cylinder block or cylinder head; 4. Cracks in the water passages of the cylinder block or cylinder head, causing high-pressure gas to enter the water passages. An engine is a machine that can convert other forms of energy into mechanical energy, originated in the UK. It can be used as a power generation device or refer to the entire machine including the power device, such as gasoline engines and aircraft engines. Its types include internal combustion engines (gasoline engines), external combustion engines, electric motors, etc.