2000 Ford F250 5.4 V8 Oil Pressure on 2000 Ford F-250 Super Duty

On overnight startup during cold weather the oil pressure reads zero but does pick up. There is no engine noise or knocking that accompanies this issue. The oil pressure guage will eventually go to normal operating range usually within a minute or so. My thoughts are a guage sending unit. Are there any other ideas? What is the procedure for replacing the sending unit?

Asked by for the 2000 Ford F-250 Super Duty
You should checked the oil pressur with a mechanical gauge to confirm the oil pressure.If gauge shows same i would consider forlower weight full synthetic oil and new filter with itegrated check valve.