VW Tiguan Idle Stalling Points to Faulty IAC Valve

Recently dealt with similar symptoms on my 2019 VW Touareg TDI. The stalling engine and unstable idle speed pointed to a contaminated intake system. The throttle body was heavily coated with carbon deposits, restricting proper air flow. The idle control valve wasnt functioning correctly because of this buildup. After a thorough cleaning of the entire intake system and throttle body, the idle stabilized completely. Common signs to check: Rough idle that fluctuates between 500-1000 RPM, Engine stalls specifically during idle, Check engine light with throttle position related codes, Poor throttle response Its important to address this promptly as contaminated components can lead to more serious engine damage if left untreated. The carbon buildup affects both the idle air control and throttle body operation. Recommended steps before visiting a mechanic: 1. Check for visible contamination around throttle body 2. Monitor idle speed consistency 3. Document exact conditions when stalling occurs 4. Get the error code read and recorded This was a significant repair requiring specialized cleaning equipment and recalibration of the idle control system.

Thanks for sharing your experience. My Tiguan had almost identical symptoms, unstable idle speed and constant stalling. Had it fixed last month and it runs perfectly now. Very relieved since the car idle problems were really starting to worry me. The throttle body cleaning and IAC valve replacement completely resolved my engine stalling issues. Just curious, do you remember roughly what you paid for the full service? Also wondering if youve had any recurring problems since the repair was done?

Since fixing the contaminated air intake system and faulty idle air control valve, my Touareg has been running flawlessly. The total repair cost came to 425€, which included a thorough cleaning of the throttle body and complete system recalibration. No recurring engine stalling or idle speed issues in the past 6 months. Regular maintenance and using quality fuel helps prevent the carbon buildup from returning. The stable idle and smooth throttle response show the repair was definitely worth the investment. If your Tiguan starts showing similar symptoms again, getting the air intake system checked early can prevent more extensive repairs. But with proper maintenance, these issues typically dont return for several years.

After getting those helpful replies, I decided to take my Tiguan to a different mechanic who specialized in VW diagnostics. The repair ended up costing 390€ which included cleaning the air intake system and replacing the IAC valve. The mechanic showed me the old components, the carbon buildup was pretty severe. The engine idle is now perfectly stable with no more stalling issues. Really glad I got it sorted before any serious engine damage occurred. The new mechanic also gave some tips about preventing future buildup, mainly recommending premium fuel and regular throttle body cleaning maintenance. Its been 3 weeks since the repair and the car runs great, no more check engine light or unstable idle speed problems. Definitely learned my lesson about addressing these symptoms early rather than waiting for them to get worse.