Could be quite a few things. I am under the assumption you already checked the fluid level. If that is the case, I would ensure there are no air bubbles in the system and or no leaks. A leak or a bubble will not allow the system to pressurize and move fluids through the radiator where the fluid can then be cooled. Also, I do know that some VW's suffer from the water pump fins cracking off which doesnt allow the fluids to circulate like they are supposed to. The last and final thing it could be is a clogged heater core. You can try by passing the heater core and see if that fixes the problem.
I would check in the following order and test after each one 1)Check Fluid Level 2)Burp System 3)Replace Thermostate 4)Bypass heater core and see if problem persists 5) All else fails replace the water pump.
You overheated the motor and warped the head and blown the head gasket is the most common problem but you need to confirm a. Fans working properly and not a Relay b. Stuck Closed Thermostat or c. LOW FLUID. d. Air trapped in the system
Answers & Comments
Could be quite a few things. I am under the assumption you already checked the fluid level. If that is the case, I would ensure there are no air bubbles in the system and or no leaks. A leak or a bubble will not allow the system to pressurize and move fluids through the radiator where the fluid can then be cooled. Also, I do know that some VW's suffer from the water pump fins cracking off which doesnt allow the fluids to circulate like they are supposed to. The last and final thing it could be is a clogged heater core. You can try by passing the heater core and see if that fixes the problem.
I would check in the following order and test after each one
1)Check Fluid Level
2)Burp System
3)Replace Thermostate
4)Bypass heater core and see if problem persists
5) All else fails replace the water pump.
Good luck
You overheated the motor and warped the head and blown the head gasket is the most common problem but you need to confirm
a. Fans working properly and not a Relay
b. Stuck Closed Thermostat or
c. LOW FLUID.
d. Air trapped in the system