2, check the pump between the various components is normal? 3, check the situation of lubricating oil. 4, check the voltage is consistent with the rated. 5, head will be different due to load problems fever. 6, if the above are no problem, then the pump rotor and stator may have gaps with the lack of cooperation. Automobile aluminum foil covered sound insulation and heat insulation interior trim series Sound Absorbing Material,Building Sound-Absorbing Cotton Material,Heat Insulation For Interior Decoration,Light Weigh Cotton Sound Absorbing Yidebao Technology Development Co.,Ltd. , https://www.zgyidebao.com1, check the wiring is there any problem? Is there any loose phenomenon?