in my opinion , # B! A+ r( Z Z5 p
1.the noise is coming from the gears .the engine oil lubricating the gear is not enough 6 i6 t! A U; p4 {' y7 {& @& N4 e* U, d# n% t7 T3 r
2.the loadmatch of the Engine and the Pump is bad or the fuel filter has big resistance