VW Touran Stalling: Idle Air Control Valve Issues Fix

Having faced a similar stalling engine issue with my 2019 VW Tiguan (2.0 TSI), I can share my experience as someone with moderate car repair knowledge. The symptoms were identical, engine stalling at idle and inconsistent idle control, especially when stopping. The check engine light also came on intermittently. After attempting basic maintenance like changing the air filter, the problem persisted. When I took it to the workshop, they diagnosed a heavily contaminated air intake system. Carbon deposits had built up significantly in the throttle body and intake manifold, affecting the engine idle stability. The complete cleaning service cost 425€, including: Professional intake system cleaning, Throttle body cleaning and recalibration, Idle control valve inspection, Diagnostic scan and reset Since the service, the idle issues disappeared completely and the engine runs smoothly again. Before suggesting specific solutions for your case, could you share: Total mileage on your Touran, When the problem first started, Whether you notice any rough idle when the AC is running, If you use premium fuel regularly This information would help determine if your issue is similar to what I experienced with the intake system contamination.

Thanks for the detailed information about the intake system cleaning. My Touran was last serviced 2 months ago at 79390km. What concerns me is that cleaning was already done during that service, yet the stalling persists. The IAC valve behavior you described matches my symptoms exactly, unstable idle control and stalling specifically at stops. The problem seems most noticeable when the engine is warm. One difference is that my idle stays relatively steady with AC on, which makes me wonder if its more than just carbon buildup affecting the air valve system. Did your mechanic mention anything about the electronic throttle position sensor when they did your service? The fact that my check engine light is constant rather than intermittent might point to a different root cause.

The constant check engine light does point to a different issue than what I initially experienced with my Tiguan. Thinking back, having a steady idle with the AC running suggests this could be more electrical than mechanical. In my case, the throttle position sensor was tested but was functioning normally. However, after the cleaning failed to resolve your stalling engine issue, I would focus on the electronic components of the idle air control system. On my previous car, similar symptoms turned out to be a failing throttle body motor. The air valve itself was clean, but the electronic actuator was not responding correctly to the ECU commands. This caused inconsistent engine idle speeds and eventual stalling, particularly after the engine reached operating temperature. The repair cost was higher at 780€, covering: New throttle body unit, Sensor calibration, System adaptation Consider requesting a specific diagnostic of the throttle body electrical components. Since basic cleaning was already performed during your recent service, focusing on the electronic control elements might reveal the true cause of your persistent idle problems.

Thanks for your suggestion about checking the electronic throttle components. I scheduled an appointment with my regular workshop for next week and specifically asked them to focus on the throttle body motor and electrical systems since we already ruled out carbon buildup. I ran a basic OBD scan at home which showed error code P0507, Idle Control System RPM Higher Than Expected. This seems to support your theory about the electronic control issues rather than just dirty components in the air valve system. The stalling engine symptoms definitely get worse when the engine is fully warmed up, which matches what you mentioned about your previous car. Will update once the shop diagnoses the exact cause. If it does turn out to be the throttle body motor causing these idle control problems, at least I know roughly what repair costs to expect based on your experience. Hopefully they can resolve it with just the throttle body replacement rather than having to dig deeper into the IAC valve system.