Engine runs oil pressure drops to zero?

No not manual

I verified with the oil light on and the manometer all the way down and the car idled that the turbo was not getting any oil (lubrication). Since my mechanic installed a new oil pump and tested. At the garage, we decided to install another brand new oil pump and test it to the max. My car had the same problem before. If the oil light turns on and pressure drops to zero while I am driving. I turn the engine off and restart the car and everything works fine for while. No overheating and no smoke. I insisted on driving with the light on and no pressure (assuming it was an electrical malfunction) and I blew the turbine. I just install a brand new turbo. I can drive fine around town but if I take the highway. Impossible.
After explaining all this to you, the question is. Could it be anything else or defective part (oil Pump) Could it be functioning randomly off and on.