Bubbles in the diesel engine water tank are generally caused by high-pressure gas in the cylinder leaking into the cooling water channel.
The causes and troubleshooting methods of blowby are as follows:
1. The cylinder head nuts are not tightened according to the specified torque. If the torque is too small and the cylinder head is not tightened, high-pressure gas will leak into the waterway. The cylinder head nuts should be tightened according to the specified torque and re-tightened regularly.
2. The cylinder gasket has been used for too long, and has been damaged or burned, causing poor sealing and air leakage. You need to replace it with a new one.
3. The cylinder head surface is uneven or deformed, causing air leakage. The cylinder head surface should be ground or replaced.
4. Improper assembly causes the cylinder liner shoulder to break and cause gas blowby. Replace the cylinder liner according to the prescribed method.
5. If the height of the cylinder sleeve shoulder is not high enough or the depth of the shoulder hole on the engine body is too large, the cylinder sleeve will not protrude enough from the engine body plane after being installed in the engine body, or even sink, and the gas will leak into the waterway from the shoulder. Therefore, a trial installation should be performed before assembly to check the protrusion and ensure that it is within the allowable range.
