Oil pressure goes up and water gauge goes low same time

The oil pressure gauge sounds normal. The oil pump is driven by the engine and when the engine RPMs go up the oil pump is pumping faster. This increases the oil pressure. As for the coolant temperature gauge I'd suspect a thermostat that's stuck open. The thermostat is supposed to be closed when the engine is cold, blocking coolant circulation until the engine is at normal operating temperature of 195°F. The thermostat will open and close some as you're driving to maintain that temperature. But if the thermostat is stuck open or partially open you can see fluctuations on the gauge. These vehicles don't have issues with air getting trapped in the cooling system, so it's not going to be that. Hope that helps! Jim