I have a 1984 380SL. New water pump, new thermostat, new radiator, new hoses, clutch fan working properly. Normal temp runs right above the 80c line on the gauge. Intermittently, and with no rhyme or reason, the temp slowly rises to just below the red line, 120c, and then comes right back down to normal. Everything checks out fine with the expection of the temp gauge. If anyone has any ideas or suggestions, I would greatl appriciate them. Thanks in advance.