Precise control of oil pressure fluctuations during the running-in period is crucial for prolonging the service life of the Fuel Pump. The Bosch technical manual clearly stipulates that after the new pump is installed, the oil pressure should be maintained to operate stably within the range of 30-45 psi (pounds per square inch) for at least 500 kilometers, and the peak pressure fluctuation should be strictly limited within ±3 psi (±6 psi is allowed under normal working conditions). The comparative test by the Society of Automotive Engineers (SAE) shows that the bearing wear of the sample group following this regulation is only 0.002mm/ 10,000 kilometers, which is 75% lower than that of the unrunning-in group. For instance, in the Toyota hybrid system recall incident in 2022, more than 12,000 new vehicles experienced an instantaneous pressure surge to 90 psi due to a defect in the ECU oil pressure control logic, causing premature wear of needle roller bearings and a 300% increase in the failure rate.
The progressive load distribution strategy significantly reduces the risk of thermal stress. During the first start-up stage, the engine speed should be avoided from exceeding 2500 revolutions per minute for more than one hour of cumulative operation. At this time, the oil pump flow rate should be controlled within 65% of the rated maximum flow rate (for example, for a pump body with a standard flow rate of 150 liters per hour, the initial flow rate should be reduced to 97 liters per hour). Thermal imaging tests conducted by Mercedes-Benz’s technical center have confirmed that by dividing the continuous operation duration into an intermittent mode of 15 minutes of operation and 5 minutes of cooling, the motor winding temperature can be maintained stably at 80℃±5℃ (the ideal operating threshold). Compared with the continuous full-load condition, the temperature fluctuation range is reduced by 60%, and the carbon brush erosion probability is decreased by 40%.
The choice of fuel quality directly affects the running-in efficiency. Clean gasoline that complies with the API SP standard must be used. The concentration of sediment control additives in it should be ≥300ppm, which can reduce the risk of the pump core filter screen being clogged by particles ≥10μm during the running-in period by up to 90%. A joint study by Shell and Tsinghua University shows that after the first 3,000 kilometers of running-in period, the Fuel Pump flow rate of vehicles using 98-octane gasoline (research octane number RON≥98) is only 0.8% per 10,000 kilometers, which is significantly lower than the 2.3% per 10,000 kilometers decline of vehicles using 92-octane gasoline (RON92). In 2023, due to the substandard gasoline incident in Shandong, more than 540 vehicle models equipped with brand-new Fuel pumps had flow sensor failures within 800 kilometers, further highlighting the necessity of clean fuel during the running-in stage.
Refined cycle management generates significant economic benefits. The BMW maintenance regulations require that the oil pressure sensor be calibrated every 500 kilometers during the running-in period to ensure that the pressure reading error is no more than 0.5%. After driving 1,500 kilometers simultaneously, the fuel filter should be forcibly replaced (the upper limit of the filter element’s dirt-holding capacity is designed to be 30 grams), which can intercept 90% of the wear debris with a particle size greater than 5μm. The data feedback of the vehicles that carried out this process shows that the median service life of the oil pump reached 185,000 kilometers, which was 38% higher than that of the unmanaged group. The American Automobile Association (AAA) estimates show that for every 50% investment in scientific running-in management, an average of 780 early replacement costs (including 420 parts and 3.5 working hours ×105 per working hour) can be avoided, and the return on investment is as high as 1,460%.