Does anyone have any experience with following recurrent problem with volvo 240 (1993): Arrow on temp gauge goes up and up and up temporarily and then returns to normal. According to mechanic, there's nothing really wrong with the car. It's not really overheating. Apparently the problem is an electrical one with the gauge and/or thermostat. I've replaced the thermostat and that seemed to work for a while, but only for a while. it drives me nuts.