I have a 2004 VW Jetta 2.0. It is overheating. I have changed the thermostat and the coolant temperature sensor thinking these things would fix my problem. My car is still running hot and the hot air inside the car blows cold. I have also noticed that once the car warms up the small radiator fan on the passenger side will turn on but the bigger one on the driver side will not. Any ideas as to what I can do?

 

u need to bleed the cooling system. u have air in it.

 

had the same problem...when i drove over 60km/h my car stayed cool but anything under that was bad, traffic was deadly. Turns out my fans were finishes, went to a recycler and bought a fan assembly for about 150$ and got the problem fixed. The radiator fan is finished but the A/C fan is still working which explains your issue and mine.

Also in my case, it turned out the thermostat was jammed open which helped the cold air from outside cool the prestone.