95 eg6 driving around, racing whatever temperature is fine.
but sometimes if im just sittin in the car parked (engine running)
temp gauge will slowly rise until it peaks, then when i start driving
around again, it'll go back down? doesnt temp doesnt always go
up, just sometimes. any ideas?

 

check to see if the fan is cutting on

 

Bleed coolant system

 

check the thermostat. if it stays shut, thats your problem. also, run idle and do as he said and check and see if fans are coming on. haha, you have what i have, an air cooled engine. except when i drive it stays cold. kinda like a motorcycle. but that's because i took the thermo. out and put a metal ring in it's place. but def. check the fans and see if, when it overheats, it boils over or atleast trys to boil over at the radiator cap.