RS6 Engine Overheating Linked to Air Flap Motor Issues

Had a very similar issue with my 2004 RS4. The check engine light was coming on intermittently and the cooling system started acting up. Had some experience with basic maintenance but this was beyond my usual scope. The diagnostic scan revealed a faulty electromechanism in the air intake system. The flap motor was not responding correctly, causing the engine to overheat during higher loads. The workshop found that the flap motor had seized due to accumulated debris and electrical wear. The repair involved replacing the entire flap motor assembly. Total cost was 590 Euro including parts and labor. Since the fix, the cooling system has been working perfectly and no more check engine warnings. Before giving more specific advice, could you share: Current mileage on your RS6, When did the overheating first start, Any recent maintenance history, Does the overheating happen more during idle or while driving, Are you noticing any unusual engine sounds when the flap should be operating This information would help determine if your issue matches what I experienced with my RS4.

Thanks for the detailed response. Last service was done 2 months ago and odometer shows 121031 KM. The car overheating started about a week ago and gets worse at idle. The grille shutter seems stuck halfway, and I can hear a clicking noise from the front when starting the car. Based on your experience, sounds like my active air flap has similar symptoms. Will get it checked at the workshop and have them run a diagnostic scan to confirm. Repair cost seems reasonable if it fixes both the overheating and check engine light issues.

Thanks for those extra details. Your symptoms definitely align with what I experienced, especially that clicking noise from the front, which was exactly what I heard before my active air flap completely failed. Since you mentioned the grille shutter is visibly stuck halfway, this strengthens the case for a failing flap motor. In my RS4, the thermal management system started behaving erratically in a similar way, with the cooling system struggling most during idle. When I had mine repaired, the workshop mentioned these flap motor failures are fairly common at around 120000 KM, so your mileage fits the pattern. Getting that diagnostic scan is the right move. Make sure they check the wiring harness connecting to the flap motor too, in my case there was some minor corrosion that needed addressing. One more thing, while they are fixing the active air flap, have them inspect the entire cooling system. When my flap motor failed, it had caused additional stress on other cooling components. Better to catch any potential issues early.

You're right, the symptoms between our cars match up closely. My engine has about the same mileage and that clicking noise at startup must be a telltale sign of the flap motor issue. Will definitely have them check the wiring and full cooling system while they are at it. Getting an appointment next week for the diagnostic scan and likely repair. The thermal management problems are concerning enough that I want this fixed before summer hits. Good to know the repair costs were reasonable in your case and that it fully resolved both the overheating and check engine warnings. Really helpful to hear from someone who went through the same air intake system issues. Will update once the workshop confirms what they find with the active air flap. Thanks for walking me through your experience with this repair.