Audi Q5 Diesel Stalling: Bad Idle Air Control Valve Fix

The idle speed issues you describe match what I experienced with my Audi A4 2012 2.0 TDI. The stalling engine symptoms at cold start were identical. After diagnosis, the problem was traced to a heavily contaminated intake system, not just the IAC valve. The engine idle problems were caused by carbon buildup blocking proper air flow. The IAC valve was actually working fine, but could not maintain proper idle control due to the restricted intake passages. The solution required a complete intake cleaning service including removal and cleaning of the IAC valve. This is a known issue with direct injection diesel engines, even with low mileage. The carbon deposits affect idle speed control and overall engine performance. In my case, it was considered a serious repair as the buildup was severe enough to impact various engine management systems. The cleaning resolved all idle control issues, no more stalling, smoother cold starts, and better throttle response. While the IAC valve replacement alone might seem like the fix, having the entire intake system cleaned is often the proper solution for these symptoms. Consider getting the intake inspected with a scope before replacing parts. The check engine light and stalling engine behavior could be fixed with a thorough cleaning rather than new components.

Thanks for sharing your experience. I had almost identical issues with my Q5 starting about 6 months ago. The engine stalling during cold starts was really concerning. After checking throttle body and air intake components, the garage found significant carbon buildup affecting idle speed control. Did the cleaning service fix the problem permanently for you? Also, could you share roughly what the repair cost? My bill came to around 450 Euro for the complete intake system cleaning, but wondering if thats in line with what others paid. No other issues have come up since the service, but keeping an eye on idle behavior just in case.

Just had my 12-month follow up and can confirm the cleaning service completely resolved all engine idle problems. The IAC valve and entire intake system are working perfectly now, no more stalling engine issues during cold starts or any other time. My total repair costs were 425 Euro for the complete intake system cleaning and IAC valve service. This seems in line with your 450 Euro bill. The investment was worth it since proper idle control has been fully restored and the engine runs much smoother overall. The mechanic explained that regular intake cleaning is preventive maintenance for these engines, even with low mileage. They recommend checking the air intake system every 30000-40000 km to prevent carbon buildup from affecting idle speed control again. After a year of trouble-free operation, I can say it was definitely the right fix rather than just replacing parts. The car maintains steady idle speeds and cold starts are no longer an issue.

The problem with my Q5 is now completely resolved. I took it to the mechanic last week after getting your helpful advice about the carbon buildup. The engine stalling during cold starts had been really frustrating, especially on winter mornings. The inspection confirmed heavy carbon deposits in the air intake system affecting the idle control. They did a thorough cleaning of the entire intake, including the IAC valve. The total service cost was 450 Euro, which seems fair based on your similar experience. Started the car this morning and the idle speed was perfect, no more stalling issues. The check engine light is now off and the engine runs noticeably smoother. The mechanic suggested scheduling regular intake cleaning every 35000 km to prevent future problems, which makes sense given how the carbon buildup can impact performance even at low mileage. Really glad I checked here before just replacing the air valve. The proper diagnosis and cleaning service saved me from unnecessary parts replacement.