After five years of putting up with my temp gauge jumping all over and
acting funny, I figured it out. I have pulled the instrument cluster four
times in the past and today I pulled it for the fifth time. After taking
apart the cluster and removing the temp, fuel and oil pressure gauges, I
found that a tiny spot on the back of the temp gauge metal housing had a
tiny bad solder joint. I hit it with my iron and wala! It is perfect.