VW Eos Radiator Fan Malfunction Causing Engine Overheat

I faced similar overheating problems with my 2014 VW CC TSI last summer. The symptoms matched exactly, car overheating, check engine light, and the car radiator fan not engaging when needed. Initial diagnosis pointed to a faulty thermal switch that wasnt sending proper signals to activate the cooling fan blade. However, after deeper inspection, the real culprit was a failing temperature control module combined with a damaged speed sensor. The speed sensor defect prevented the system from accurately measuring engine temperature and fan engagement timing. The repair involved replacing both components since they work as an integrated system. This was definitely a serious issue that required immediate attention, as continued driving could have led to severe engine damage. The thermal switch and temperature control system in these VW models are known to develop issues around the 30000-40000km mark. My suggestion would be to get a second opinion from a VW specialist. They should specifically check the thermal switch, speed sensor, and temperature control module. These components are crucial for preventing car overheating, and replacing just one might not solve the underlying problem if multiple parts are affected.

Thanks for sharing your experience, its very similar to what I went through. Would you mind telling me what the final repair cost was? I am curious since my local shop quoted quite high. Also, have you experienced any cooling system issues since the repair was done? The temperature control module replacement seems to be the right direction as my symptoms match yours exactly. The car overheating combined with the radiator fan behavior definitely points to the electrical system rather than mechanical components.

Thanks for checking back. Since my last reply and getting the repair done, I have not experienced any car overheating issues. The radiator fan is now working perfectly and engages exactly when needed. The car cooling system has been running smoothly for several months. The total repair cost came to 250€ for fixing the speed sensor defect. This was actually less than I initially expected, especially considering how critical this component is for proper engine cooling function. The thermal switch testing was included in the diagnostic fee. The fan noise is now normal and predictable, it kicks in at the right temperature and cycles properly. Looking back, getting this fixed was definitely worth it to prevent potential engine damage from chronic overheating. If your quote is significantly higher, you might want to get a second opinion, but make sure they specialize in VW cooling systems.

Thanks for the helpful input. Just wanted to close this thread with my repair experience. I took the car to a certified VW specialist who properly diagnosed the issue. The thermal switch was indeed faulty, but they also found the fan motor itself was drawing excessive power. The total repair ended up costing 340€, which included replacing both the thermal switch and fan motor assembly. The engine cooling system is now working perfectly, no more overheating issues and the fan kicks in exactly when it should. The repair took about 3 hours total. Since then, the check engine light has stayed off and engine temperature remains stable even in stop-and-go traffic. The cooling system is working like new and the fan blade spins up smoothly without any unusual noise. Really glad I got a second opinion instead of going with the first shops much higher estimate. Always worth checking with specialists who know these specific models well.