VW Phaeton Radiator Fan Failure Causing Engine Overheat

Had a similar issue with my VW Passat 2013 gasoline last summer. The overheating symptoms matched exactly, fan blade not spinning and check engine light activated. Initial diagnosis revealed a faulty thermal switch that wasnt properly triggering the fan motor. However, after replacing the switch, the cooling system still had issues. Further testing showed the fan motor itself had failed completely. The cooling system repair required: Replacing the fan motor assembly, Installing new thermal switch, Cleaning the radiator thoroughly, Checking coolant levels and circulation This was a serious repair that needed immediate attention to prevent engine damage. The fan motor failure can quickly lead to severe overheating issues, especially in slow traffic or when idling. Recommendation: Have the entire cooling system checked professionally. Start with testing the thermal switch and fan motor operation. Since your Phaeton shares similar cooling system architecture, these components are likely culprits. Dont drive the car if its showing overheating symptoms, as this could cause permanent engine damage. The repair took about 4 hours at the shop. Its worth getting fixed properly rather than trying temporary solutions, as proper engine cooling is crucial for engine longevity.

Thanks for sharing your experience with the fan motor and thermal switch replacement. Your description sounds exactly like what Im dealing with on my Phaeton. The temperature control issues and fan noise match my symptoms perfectly. Just wondering, do you remember the total cost for your repair? Also, has everything been working properly with your cooling system since the fix, or have you noticed any other issues with the car radiator?

Thanks for asking about the follow-up. Since getting the radiator fan defective fixed at the mechanic, my cooling system has been working flawlessly. The temperature control now functions exactly as it should, with no unusual fan noise or overheating issues. The total repair cost was 250€ for the speed sensor that was causing the fan blade malfunction. This was actually less expensive than I initially feared, considering the symptoms pointed to a potentially bigger problem with the engine cooling system. The car radiator has been operating perfectly for over 8 months now. No recurring issues with the cooling system at all. The fan kicks in exactly when needed and maintains proper engine temperature, even during extended idle periods or slow traffic. Would definitely recommend getting it checked soon though, waiting too long with these symptoms could lead to more extensive damage and higher repair costs.

Thanks for the helpful advice. I actually just got back from the mechanic and wanted to share how it turned out. My car radiator issues ended up being quite similar to what was described. The thermal switch was completely dead and the radiator fan motor had significant wear. The mechanic found the temperature control unit was also showing early signs of failure. Rather than doing partial fixes, I opted for a complete cooling system overhaul: Total cost breakdown: Fan motor assembly: 320€, Thermal switch: 85€, Labor: 180€, System flush and new coolant: 65€ Total came to 650€, which was more than initially hoped but less than feared. The car runs perfectly now, no more overheating issues and the engine temperature stays consistently normal. The radiator fan kicks in exactly when it should. Really glad I got this sorted before any serious engine damage occurred. The shop did great work and actually showed me the worn parts afterward. Definitely worth the investment to avoid bigger problems down the road.