2003 Ford F-150 GUAGES PEGGIG ON HIGH

Driving home from work yesterday my oil pressure gauge spiked to high. I pulled over and shut the moter off and opened the hood. I was stopped for about 10 minutes and I checked the oil, witch was fine. I returned to the truck and started it up again and the pressure was fine. I took it to a shop and they told me the error code was from a hot cylinder, but the temp was normal when I restarted the truck. Today driving home the temp was fine and as I watched the guage (temp guage) it shot right to hot, so I pulled over again and opened the hood where everything looked fine (no steam or funny noise) and got back in the truck. I turned the key and the temp guage read normal. Now I was out of the truck no more then 2 minutes. Any Ideas