VW Transporter Stalling: Bad Idle Control Valve Fix

As a VW Golf 2.0 TSI (2011) owner, I encountered nearly identical idle speed issues. The engine would stall at traffic stops while running perfectly at higher RPMs. The IAC valve turned out to be severely contaminated, but the root cause was actually a larger carbon buildup issue in the intake manifold. The diagnosis revealed that both the idle air control valve and intake ports were clogged with carbon deposits, restricting proper airflow. This is a known issue with direct injection engines. The stalling engine symptoms disappeared completely after a thorough intake cleaning service and IAC valve replacement. A proper fix requires: Complete intake manifold removal, Professional cleaning of intake ports, IAC valve replacement, Resetting engine idle parameters This is not a quick fix job, the intake manifold removal alone takes significant labor time. The carbon buildup can cause serious engine damage if left untreated, potentially leading to failed valves or scoring of cylinder walls. For accurate diagnosis, have the shop check both the air valve function and intake port condition. Simply replacing the IAC valve without addressing potential carbon buildup might not solve the underlying problem. Testing the idle control valve operation with a scanner while monitoring idle speed fluctuations can help confirm if its the primary issue before any repairs begin.

Thanks for sharing your experience. The exact same thing happened with my Transporter last winter, rough engine idle and constant stalling at traffic lights. Got it fixed by cleaning the throttle body and replacing the idle air control valve. Really wondering what kind of repair costs you faced and if the stalling issue has stayed away since the fix? Mine seems ok for now but keeping an eye on the idle speed since these engine idle problems can sometimes come back.

Just following up, yes, the stalling problem completely disappeared after fixing the bad idle air control valve and cleaning the heavily contaminated intake system. The total repair cost came to 425€, which included a thorough cleaning service and the new air valve component. The throttle body was in particularly rough shape, but the professional cleaning made a huge difference in how the engine runs. The engine idle has been perfectly stable for the past 8 months with no signs of the previous issues returning. Regular maintenance of the air intake system seems key to preventing these problems from coming back. The mechanic recommended using a quality fuel system cleaner every 15000km to help reduce carbon buildup and keep the idle speed steady. If your engine starts showing any irregular idle patterns again, getting the air intake checked early can prevent more expensive repairs later. The investment in proper cleaning was definitely worth it compared to risking damage to other engine components.

Thanks for the advice. Just wanted to share how my repair experience went. Finally took it to a local shop specializing in VW repairs. The mechanic found heavy carbon deposits in the throttle body and a failing idle control valve. Total bill came to 390€ including parts and labor. They did a complete throttle body cleaning and installed a new control valve. The car idle is now rock steady, no more stalling at red lights or struggling to maintain speed when stopping. The repair took about 3 hours and the shop showed me the gunked-up old parts. Pretty eye-opening to see how dirty the system had gotten. They suggested using a fuel system cleaner every oil change to prevent future engine idle issues. Really relieved to have this fixed before it caused bigger problems. The engine runs smoother overall and the check engine light is finally off. Will definitely stay on top of the maintenance schedule to avoid another round of idle problems.