I just bought my very first camaro three days ago. It is an 89 with the 2.8L. The temprature gauge pegs out and stays there untill I tap the gauge a couple of times and then it comes back down. I think I have narrowed that down to a bad ground. Also the gauge is reading about 240 before the electric fan turns on and then cools it down to about 210. Is this gauge giving the correct readings. Also wile going down the highway the gauge reads about 120. Why such a big fluctuation in temps. Please help me I am still learning about the car.