Linde H30T H2X. The hydraulic fan seems not be efficient. When I start the engine, the fan will spin, as I rev the engine up and down, I can hear the fan increase and decrease, but eventually after revving the engine up and down the fan will come to a stop with engine running. If I restart the engine the fan will start rotating again. If I leave the engine running the fan will not spin. When I unplug the flow solenoid the fan will run at constant speed, and plug it back in will run until I rev the engine up and down again. I have done the washer mod to the flow valve. I have pulled the rad, cleaned it inside and out, replaced thermostat and seal, flushed cooling system, replace hydraulic temp sensor, cleaned cooling temp sensor, replaced muffler. Im at a lost and hope someone can help out.