A4 Radiator Fan Issues Causing Engine Overheating

Had the exact same cooling system issue on my 2007 A4 2.0T last month. The radiator fan was running erratically, causing engine temperature spikes even during regular driving. Initial diagnosis pointed to the fan motor, but it turned out to be a corroded wiring connector at the electric fan assembly. The connection degradation caused intermittent fan operation, leading to inconsistent cooling performance. Key things that indicated the connection problem rather than a faulty fan clutch: Fan would sometimes work normally, No mechanical noise from the fan clutch, Engine temp would fluctuate rather than steadily increase The repair involved cleaning the connector pins and replacing the wiring harness section connected to the cooling fan motor. This was a serious issue that needed immediate attention, as continued overheating could have led to engine damage. Recommend checking the electrical connections first before replacing any major components. A basic voltage test at the fan connector while the engine is running can help identify if power is reaching the fan motor consistently. If the connectors look clean and testing shows proper voltage, then investigating the fan motor or fan clutch would be the next step.

Thanks for sharing that repair experience. The wiring fix seems like a smart first step before replacing costlier parts. I actually had similar vehicle overheating problems with my 2005 A4, where the electric fan would out of nowhere stop working during city driving. The temperature control went completely unreliable. After reading your post, I checked my own connections but sadly the issue was the electric motor itself. The fan assembly needed full replacement to restore proper engine cooling. Did you remember roughly how much the wiring harness repair cost you? Also curious if youve had any cooling system problems since the fix?

Glad I could help with your cooling system diagnosis. The wiring repair at the shop cost me 95 Euro total, which primarily covered cleaning and fixing the cable connection to the electric motor. Much cheaper than replacing the entire radiator fan assembly. Since repairing the faulty connector, the engine cooling system has worked flawlessly. The electric fan now kicks in consistently when needed, maintaining proper temperature control. No more vehicle overheating issues or erratic fan behavior during any type of driving. Your case with the failed fan motor is also common, these cooling system components can fail in different ways. At least checking the wiring first helped rule out the simpler fix before investing in a new fan assembly. Regular temperature monitoring is still good practice, but proper fan operation makes a huge difference in preventing engine overheating.

Thanks for the helpful advice. After dealing with persistent vehicle overheating, I finally got my cooling system properly diagnosed and fixed. The mechanic I found charged 380 Euro for a complete radiator fan replacement, including labor. The fan clutch turned out to be fine, but the electric motor was definitely shot. During testing, they found the motor would only work about 30% of the time, explaining the inconsistent engine cooling. The new fan assembly has completely solved the temperature spikes. Been driving for two weeks now and the engine cooling is working perfectly. Temperature gauge stays steady even in slow traffic. Much better experience than my previous mechanic who just kept telling me to top up the coolant. Sometimes you need to trust your instincts and find a shop that really diagnoses the root cause.