The oil return pipe, as the name suggests, is used to return fuel. It is usually located in the car’s fuel pump and is used to return fuel from the engine to the fuel tank. There is an oil return pipe in most cars.

Although the rear oil pipe in the engine is an inconspicuous small part, its role is irreplaceable. It plays an important role in the normal operation of the engine.

When the fuel pump works, it will supply fuel to the engine, and a certain pressure will be formed to supply the nozzle for fuel injection. From a design point of view, the oil transfer pump cannot achieve quantitative on-demand supply. Therefore, the amount of oil supplied is generally more than the amount used. Of course, due to the precision of the equipment, it is inevitable that some oil will leak out. This increases the pressure within the injector chamber. When a certain pressure is reached, various failures will occur.

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At this time it is necessary to rely on the oil return pipe. In other words, the excess fuel will return to the fuel tank through the return pipe, waiting for the next use. Of course, those excess fuel vapors collected by the carbon canister can also be returned to the fuel tank. This can not only save fuel and reduce fuel consumption, but also relieve the pressure on the engine, eliminate adverse phenomena, and ensure the normal operation of the engine.

The oil return pipe not only has this function, it is also an important window for troubleshooting engine faults.

After disassembling the engine’s oil return pipe, you can directly and quickly determine whether the pressure of the fuel system in the engine is normal. Or the fault can be indirectly determined by the oil return condition of the oil return pipe. If the oil return is rapid, this proves that the fuel pressure is basically normal. If there is no oil return or the oil return is slow, it proves that the fuel pressure is insufficient. Then we need to check and repair parts such as the electric fuel pump.