JUST BOUGHT A 2002 VW JETTA 1.8 TURBO. TEMPERATURE GUAGE WILL STAY AT 190 FOR AWHILE THEN START TO INCREASE, BUT THIS IS ONLY WHEN DRIVING DOWN THE ROAD. IT WILL NOT OVERHEAT WHEN PARKED AND RUNNING (EVEN WHEN HOLDING A REV AT 3000 RPMS). PLENTY OF HEAT COMING FROM HEATER. PLENTY OF FLUID IN THE RESERVOIR. ANY SUGGESTIONS? IS IT THE TRANSMISSION FLUID OVERHEATING?

 

You said plenty of fluid in the reservoir? Are the fans turning on? They also cool your engine while driving, when it starts overheating, pop your hood see if they are running.

 

[:-] Most problems are common on all vehicles. Does the fan kicks in when the engine heats up. Is there enough 50/50 water and coolant mix in the radiator. Is the fan fuse blown or the wrong amp fuse was put in. You have to eliminate the most simplest of things to the most difficult.