Audi S1 Fan Failure Causes Dangerous Engine Overheating

I had this exact issue with my 2016 Audi S3 last summer. Have some experience working on cars, mostly basic maintenance and diagnostics. The engine cooling problem turned out to be a faulty connection between the electric fan motor and its control module. The electric fan wasn't engaging because of a corroded plug connection. Initially thought it needed a complete fan motor replacement, but the actual fix was much simpler. Took it to my regular workshop where they diagnosed the issue by testing the fan motor circuit. They cleaned the connector, applied dielectric grease, and properly reseated all connections. Total cost was 95 Euro including diagnostic time. Quick test you can do: When the engine is warm but not running, turn the AC to maximum. The electric fan should kick in. If it doesn't, you likely have an electrical issue with the fan system. To help diagnose this further: Have you noticed if the fan ever works, even briefly? Does the problem get worse in stop-and-go traffic? Are there any warning lights on the dashboard? What engine size does your S1 have?

Last service done at 193148 KM. After checking all your suggestions, I found something interesting. The fan clutch seems completely stuck and wont engage at all, even with AC on full. Did the electrical test you mentioned and got no response from the electric fan motor. Tried the AC test multiple times and no fan engagement whatsoever. The problem definitely gets worse in traffic, and temperature quickly rises within minutes of stopping. No warning lights showing on the dash yet. Think I will get it checked professionally since the engine cooling system seems to need urgent attention. Thanks for pointing me in the right direction with those diagnostic steps.

Good to hear back from you. Based on what you described, especially the completely unresponsive fan motor and rapid temperature increase in traffic, this sounds very similar to what I experienced with my S3. Since the fan shows zero response even with AC on max, its likely more than just the corroded connection I initially suspected. The radiator fan not engaging at all points to either a completely failed electric motor or a blown fuse/relay in the cooling system circuit. Quick things to check before the shop visit: Inspect fuse box for any blown cooling system fuses, Listen for any humming or clicking when AC is turned on, Check if the temperature control module connector is firmly seated In my case, after the initial connection fix, I ended up having intermittent overheating issues again about 2 months later. The vehicle temperature control system needed a full diagnostic, and they found the fan motor itself had failed. The complete repair including parts and labor ran about 450 Euro. Given your mileage and symptoms, preparing for a possible fan motor replacement might be wise. Would definitely get it looked at soon since consistent overheating can lead to more serious engine damage.

Thanks for the detailed follow-up and diagnostics. I checked the fuses and they all appear fine. You were right about checking for sounds, no humming or clicking when turning on the AC. Also verified the temperature control module connector, and its seated properly. Given the symptoms and my high mileage, I suspect youre right about it being a complete fan motor failure. Made an appointment with my mechanic for next week. Will update once I know the exact issue and repair cost. The radiator fan situation definitely needs sorting quickly, especially since the cooling system seems completely compromised at this point. Really appreciated the testing suggestions, helped confirm this isnt just a simple connection issue. This matches what you experienced with yours, starting simple but ending up needing a full replacement. Will budget around 500 Euro based on your repair costs. At least now I can go in knowing what to expect. Thanks for walking me through the diagnostic steps and sharing your similar experience. Having this information before the shop visit helps a lot.