Don't underestimate the vent hole on the fuel tank cover

So, what exactly is the role of the air holes on the fuel tank or fuel tank cap?

One situation is that during engine operation, the completely closed fuel tank will form a certain vacuum due to the gradual lowering of the oil level, resulting in the loss of fuel pump suction capacity. Another situation is that when the temperature inside the tank is high, the fuel will constantly evaporate up, and the oil vapor will make the pressure in the tank increase rapidly.

In the transportation process, diesel fuel is consumed, the fuel level is reduced, and the fuel tank will form a certain vacuum. If the ventilation holes are clogged, the fuel tank will form a negative pressure due to the decline in the fuel level, causing inward concave deformation.

Clogging of the ventilation holes will not only cause deformation of the fuel tank, but may also prevent the fuel pump from pumping out fuel. It can also lead to sudden stalling and lack of power while driving. The fuel tank may even rupture due to serious deformation, which may lead to fuel leakage or even fire and explosion, etc.

When you perform maintenance, open the gas tank cover, there will be an air flow sound. This sound is divided into two kinds, one is the air out sound, this sound is normal, especially in the hot summer; the other is the suction sound, if there is a suction sound, you have to pay attention to it, this shows that the pressure in the tank is lower than the external pressure, this situation, there may be a permeable hole clogging or different degrees of clogging.