Love your videos on YouTube, I've used em many times. Came here today because I'm stumped. I've replaced the thermostat, coolant sensor, water pump is not too old, belts are all in good shape, fluid is full but my car still shows hot sometimes. I just drove about 50 miles, the whole time the temp gauge was normal. Shut the car off for about 5 minutes to run my sons laptop into his school. Came back out to head home and the temp gauge read hot. What can cause this?!