Hello! I just installed a pressure gauge on my pressure washer today. I have a 4000 psi 4.2 gpm cold water unit.When I let the machine run without pulling the trigger the pressure fluctuates between 3000 and 4000 psi.The machine will idle at 3000 psi for about 8 seconds then the psi rises to 4000.When this happens the spring on the unloader moves a bit.Just wondering if this happened to any of you? Thank You!