VW Caddy Fan Malfunction Leads to Engine Overheating

Had the same temperature control issues on my 2019 VW Passat. The engine cooling system showed similar symptoms, inconsistent radiator fan operation and overheating warnings. The root cause turned out to be a failing thermal switch, which wasnt properly regulating the cooling system. When the switch malfunctions, it cant properly signal the fan to engage at the right temperature thresholds. This creates a cycle of overheating since the car radiator isnt getting proper airflow when needed. The repair required replacing both the thermal switch and the temperature sensor. It was a serious issue that needed immediate attention since continued overheating risks major engine damage. The job took about 3 hours at the shop. Important: Have this checked soon. A faulty cooling system can lead to: Warped cylinder heads, Blown head gaskets, Engine block damage, Complete engine failure The check engine light in combination with overheating strongly suggests a thermal switch or sensor problem rather than a mechanical fan issue. A diagnostic scan will confirm the exact cause.

Thanks for sharing your experience. My Caddy had nearly identical symptoms last month, definitely nerve-wracking when the engine starts overheating. After replacing the thermal switch and sensor, has the radiator fan been working consistently? The fan motor on mine occasionally still sounds a bit rough even after the fix. I was quoted quite a range of prices at different shops for the temperature control system repair. Would you mind sharing what you ended up paying? It would be helpful to know if mine was reasonably priced. Also, have you noticed any other cooling-related issues pop up since the repair?

After the repair last month, the radiator fan has been working perfectly, no more inconsistent operation or overheating issues. The mechanic confirmed it was a defective speed sensor causing the fan motor problems. A diagnostic scan showed clear readings once replaced. The total repair cost came to 250€, which included parts and labor. The price seems reasonable considering the specialized nature of engine cooling system work and the importance of using quality components. Since fixing the radiator fan defect, everything has been running smoothly with normal operating temperatures. No other cooling-related problems have emerged. The fan blade spins quietly now and engages exactly when it should based on engine temperature. If your fan motor still sounds rough, it might be worth having it checked again. Sometimes multiple components in the cooling system can wear down simultaneously, especially if the initial problem went unchecked for a while.

Thanks everyone for the helpful insights. Just wanted to update on my repair experience. Took the car to a certified VW shop last week after the overheating continued. The diagnostic revealed a failed temperature control module along with a worn fan motor bearing. The mechanic showed me how the radiator fan was actually running at inconsistent speeds, explaining the rough sound I mentioned. Total cost came to 385€, more than expected but they replaced both components plus did a full cooling system inspection. The fan noise is completely gone now and the engine temperature stays perfectly steady, even in stop-and-go traffic. One useful tip from the mechanic: they recommended checking the coolant level monthly since low coolant was putting extra stress on the cooling system. No more car overheating issues since following this advice. Been about 2 weeks since the repair and everything is running great. Really glad I got it fixed before any serious engine damage occurred.