[oldmarine]

According to the FSM, the needle on the gauge is controlled by the ECM according to the following schedule: If the oil pressure is between 1 psi and 20 psi, the needle will show at the lower end of the normal scale, as you pictured it. If the pressure is between 75 and 110 psi, it will be at the upper end of the normal scale. If the oil pressure is between 20 psi and 75 psi, the needle will move along the normal range of the gauge. If pressure is below 1 psi, it will move to the "L" mark, and if it is above 110 psi, it will move to the "H" mark. There is no way from viewing the gauge in this picture to determine if the pressure is 1 psi or 20 psi or somewhere in between. But apparently, the engineers felt that 1 psi was 'normal'.

 

[oldmarine]

You may want to put a direct reading pressure gauge on the fitting that the oil pressure sending unit is on right now, and see what the oil pressure is. Or you may want to put a tee there, and have the direct reading gauge in the cab also.