Wifes car. Oil pressure guage reads 0. She said it was running fine but after about 5 minutes it started running hot so she parked it. I checked the oil and it is full but I don't really want to start it up and damage the engine. Do you think it could be the sending unit or something more serious? I would greatly appreciate any help.

easiest thing to do to me would be pop off the front valve cover and run it a minute to see if you are getting oil to the rockers