whats up guys was over at rainforests house and i changed my oil and a lower radiator hose. anyway on the way to his house my temp guage shot up about 3 notches away from hot. so i turned the car off rolled it into a gas station and checked everything out. my radiator fluid was up radiator cap was pressurized and all of my hoses were intact. my question is this either its the thermostat or temperature sensor correct? what else could it be...as i know the engine isnt actually reaching the high temps the gauge says it is because i went over to chris and it happened again. however this time the car had only been running for like 5 minutes and it still wasnt fully up to temp yet the temp guage said it was running hot again.

what does everyone suggest?

im going to start replacing the sensor thermostat..etc..until i fix the problem what should i do first...