Professional Generator Supplier
 Share the function of various functional holes on the diesel engine


11 2023

For professional diesel generator manufacturers, all the parts on the diesel engine are well known, so I believe that many unit users do not know what the holes on the top of the diesel engine are for, what are their names, etc. Question, below, the power will introduce the various functional holes of the diesel engine one by one.


1. The drain hole at the lower end of the cooling water pump housing

This hole is used to drain water leaking from the water seal between the impeller and casing. Make sure it is unblocked during use, otherwise the leaking water will not drain out and enter the bearing seat, thereby accelerating the damage of the bearing.


2. The lubricating oil hole on the small end of the connecting rod and the bushing

The function of this small hole is to make lubricating oil delivered to the small end of the connecting rod and its bushing in time to lubricate. If this hole is blocked, it will accelerate the wear of the bushing, reduce its service life, and cause the engine to run prematurely. to produce a knocking sound.


3. Intake and exhaust holes on the radiator box

When the engine is working, the rise in water temperature in the closed cooling system will vaporize the cooling water and generate high pressure, which will cause the radiator core tube to burst and leak water. And when the engine load becomes smaller or stops running, the water vapor in the cooling system will condense into water to lower its pressure, and the pressure difference may cause the core tube to be crushed, hindering the normal circulation of cooling water. For this reason, an air vapor valve is provided on the radiator cover, and a public air hole is arranged to communicate with the atmosphere.

When the water temperature rises, water vapor is generated in the radiator, the steam valve opens, and the water vapor is discharged from the hole; when the water temperature drops, the pressure drops, the air valve opens, and the outside air enters the radiator through the hole, thus ensuring the radiator The internal pressure is stable. During use, ensure that this hole is unblocked and cannot be blocked, otherwise it will affect the heat dissipation performance of the radiator and engine.

4. The vent hole on the fuel tank cap

In order to prevent the fuel in the fuel tank from splashing due to vibration, the escape of oil vapor and the entry of external dust, the fuel tank should be covered and sealed. However, when the oil level is lowered due to fuel consumption, a certain degree of vacuum will be formed in the fuel tank, causing the oil pump to lose its ability to absorb oil; in addition, when the temperature is high, the fuel evaporates, and the oil vapor will cause excessive pressure in the fuel tank. Both of these situations require automatic communication with the atmosphere when there is a pressure difference between the inside and outside of the fuel tank. For this reason, vent holes are provided on the fuel tank cap to balance the air pressure inside and outside the fuel tank.

During use, ensure that the vent hole on the fuel tank cap is unblocked. If the vent hole is blocked or if the fuel tank cap is lost and the fuel tank port is tied dead with a plastic cloth, the inside of the fuel tank will form a negative pressure due to the drop of the fuel level when the engine is running, resulting in unstable engine operation, power drop, automatic flameout and Difficult to start when the engine is hot.

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