Smart Roadster Fan Failure Causing Engine Overheating

I experienced similar cooling system issues with my Smart ForTwo 2008. The radiator fan not engaging properly is a common problem that can lead to overheating. When my car showed these symptoms, the thermal switch was indeed faulty, preventing proper fan activation at the right temperature thresholds. The diagnostic revealed that the thermal switch was sending incorrect signals to the fan motor. Once replaced, the radiator fan started working correctly again, engaging at the proper temperature points. This prevented further overheating issues and resolved the check engine light. This was a serious issue that needed immediate attention, as continued overheating could have led to engine damage. The repair involved testing both the fan motor and thermal switch connections, but the main culprit was the thermal switch itself. The fan blade assembly should also be inspected while doing this work, as debris can sometimes affect its operation. In my case, the mechanic found some minor debris around the fan motor housing that needed cleaning. When diagnosed early, this repair prevents more extensive cooling system damage. Having the thermal switch and fan operation checked should be your first step before more expensive components like the radiator need replacement.

Thanks for sharing your experience with the thermal switch replacement. I had almost identical symptoms on my Roadster about 6 months ago. After replacing both the fan motor and temperature control module, the cooling system works perfectly now. Did you keep track of the repair costs? And has everything been running smoothly since the fix? The fan noise on mine is now normal and consistent when the engine gets hot, which is reassuring. I recommend keeping track of the car radiator temperature for a while after such repairs. While my issue was resolved, it would be helpful to know if you encountered any other cooling-related problems afterwards.

Yes, I can confirm everything has been running smoothly since getting the radiator fan fixed. The speed sensor was identified as the defective component, costing 250€ for the complete repair including labor. The car cooling system now works exactly as it should, the fan kicks in consistently when needed and maintains proper engine temperature. The car radiator temperature has stayed steady for the past 6 months with no fluctuations or warning lights. The fan motor engages properly at the right temperature thresholds, unlike before when it was barely spinning. Having a properly functioning cooling system definitely provides peace of mind, especially during longer drives. My mechanic did a thorough job testing the entire setup after the repair. The consistent fan noise you mentioned is exactly what I experience now too, it's a good indicator that the system is working correctly. No additional cooling-related issues have emerged since the fix.

After seeing your advice, I took my Roadster to a trusted mechanic last week. The diagnostic revealed both a faulty thermal switch and worn fan motor, just as suspected. Total repair cost came to 480€ including parts and labor. The engine cooling system now works perfectly. The fan blade spins up properly when needed, and engine temperatures stay normal even in slow traffic. The check engine light is gone and the car runs much better overall. My mechanic was thorough, testing the entire cooling system after the repair. He also cleaned some debris around the car radiator that had built up over time. The service included a cooling system pressure test to ensure there were no leaks. Money well spent compared to risking major engine damage. For anyone facing similar symptoms, getting it checked early definitely saved me from bigger problems down the road.