Q5 Fan Motor Issue Causes Dangerous Overheating

I experienced a very similar issue with my 2015 Audi Q3 2.0 TFSI last summer. With some experience working on cars, I initially thought the electric fan motor had failed completely. The overheating symptoms matched exactly, temperature rising during idle and slow city driving, with the radiator fan not engaging when it should. After checking fuses like you did, I took it to my regular workshop. Turns out it wasnt the fan motor itself but a damaged wiring connector going to the fan control module. The constant engine bay heat had made the plug brittle, causing poor contact. Total repair cost was 95 Euro including diagnosis and fixing the connection. Before jumping to replacing the entire fan motor, you should have the electrical connections checked thoroughly. A faulty connection can mimic a dead fan motor but costs much less to fix. To better assist with your specific case, could you share: Does the fan work at all, even at high temperatures? Have you noticed any error codes? When did you last have the coolant level and condition checked? Does the engine cooling system have any history of repairs? This would help determine if your issue matches what I experienced or if there might be other factors involved with the engine cooling system.

Both the fuse box and fan control module were tested at my last service at 55540KM. The electric fan actually works intermittently, sometimes engaging at high temperatures, other times staying completely inactive. My mechanic ran diagnostics and found no error codes, which made initial troubleshooting more challenging. The cooling system flow test came back normal, suggesting the coolant circulates properly. However, the temperature sensor readings were inconsistent when tested with diagnostic equipment. This points to a potential issue with the sensor rather than the fan motor itself. I plan to have the temperature sensor replaced first since its a cheaper fix compared to a complete fan motor assembly. The quoted repair cost is around 180 Euro for parts and labor.

Good to hear back about those diagnostic results. Having gone through similar issues with my Q3, the intermittent fan operation and inconsistent temperature sensor readings definitely ring a bell. After my wiring connector fix, I actually ended up replacing the temperature sensor as well about 2 months later when the overheating issues returned. The electric fan would out of nowhere kick in and out, just like yours. The engine cooling system would work perfectly fine for a few days, then start acting up again. The temperature sensor replacement solved the problem completely. The labor was straightforward and the total cost was close to what youve been quoted, I paid 165 Euro. Since then, the radiator fan engages consistently when needed and the engine temperature stays stable even in heavy traffic. Its worth mentioning that a faulty temperature sensor can lead to more serious problems if left unchecked, as incorrect readings might prevent proper engine cooling management. I think youre making the right call starting with the sensor replacement. Once you get it done, monitor the temperature gauge behavior for a few days, particularly during city driving. If the overheating persists, then looking into the fan motor might be necessary, but based on my experience, the sensor is likely the culprit here.

As the initial poster, I really appreciate all the feedback about the overheating issues. Got the temperature sensor replaced yesterday for 175 Euro and wanted to share an update. The vehicle overheating problem has mostly resolved. The electric fan now engages consistently when engine temperatures rise, especially during city driving and idle. The temperature gauge stays firmly in the normal range, even in stop-and-go traffic. The mechanic confirmed the old sensor was giving erratic readings, causing the fan motor control system to malfunction. Having a properly functioning engine cooling system again gives great peace of mind. The repair cost was well worth it, especially compared to potentially replacing the entire fan assembly. Will keep monitoring the temperatures over the next few weeks, but so far the car runs perfectly. Thanks again for helping me avoid an unnecessary and more expensive fan motor replacement.