Failing Q8 Electric Fan Causes Dangerous Overheating

Having some experience with similar cooling issues, I dealt with this exact problem on my 2020 Audi Q7. The vehicle overheating symptoms were nearly identical, rising temperature gauge during idle and slow traffic situations. Initially, I also suspected the electric fan, but it turned out to be a faulty wiring connection to the fan clutch assembly. The engine cooling system was actually fine, but the fan wasnt receiving proper signals due to this electrical issue. The repair involved checking the entire temperature control system and ultimately replacing a damaged wire harness connector. Total cost was 95 Euro for the repair, including diagnostic work. Before jumping to conclusions about your Q8, it would help to know: Does the overheating occur more frequently in specific conditions? Have you noticed any unusual noises from the fan area? Are there any warning lights on the dashboard? Has the vehicle had any recent cooling system maintenance? This information would help determine if youre dealing with a similar electrical issue or if its something else in the cooling system.

Thanks for sharing those details. After my last service at 67727 KM, I did notice a slight buzzing sound from the fan motor area before the temperature started climbing. No warning lights though. The overheating seems most pronounced when the outside temperature is above 25 degrees, especially in stop-and-go conditions. The electric fan appears to run constantly now, even when it shouldnt, which makes me think the temperature control module might also be involved. Based on your experience, I will have the wiring connections checked first before replacing any major cooling system components.

Thanks for the additional details. That buzzing sound from the fan motor area is quite telling. I had the same symptom with my Q7 before the issue became more serious. While my problem was the wiring connector, your constant fan operation points more toward a failing temperature control module. The electric fan running non-stop suggests the system isnt properly reading engine temperature signals. This continuous operation can actually strain the fan motor over time and lead to premature failure. Since fixing my wiring issue, I learned its crucial to check the entire temperature control system hierarchy: 1. Temperature sensors 2. Control module 3. Fan motor connections 4. Fan clutch assembly Given the symptoms you describe, especially the constant fan operation and overheating in warmer conditions, Id recommend having both the temperature control module and the fan motor assembly tested. The continuous running could be the system compensating for a failing component. The repair costs can vary significantly depending on the actual fault. While my wiring fix was relatively inexpensive at 95 Euro, a complete temperature control module replacement typically runs around 350 Euro if thats needed. Let us know what the diagnostic reveals. Your symptoms sound quite similar but possibly more advanced than what I experienced.

Thanks for the input. I had my Q8 checked today, and it turns out the radiator fan control module was indeed the culprit, just as suggested. The constant running of the electric fan was happening because the module wasnt properly regulating the fan speed based on engine temperature. The repair cost came to 375 Euro including labor, which seems in line with the estimate provided. The engine cooling system is now working perfectly, no more overheating issues even in heavy traffic. The buzzing noise is completely gone too. For anyone else experiencing similar overheating problems with constant fan operation, definitely have your temperature control module checked first. This systematic approach saved me from unnecessarily replacing the entire fan assembly, which would have been much more expensive without solving the actual problem.