V Klasse engine stalling at idle

I see you are experiencing difficulty with your Mercedes-Benz V Klasse The symptoms you describe suggest a potential malfunction within the idle air control system The IAC valve is a plausible candidate However, a heavily contaminated air intake manifold can also precipitate these issues I encountered a similar predicament in my previous vehicle, a Volvo V70, albeit with a diesel engine The diagnostic process revealed substantial carbonaceous deposits within the intake manifold, restricting airflow and ultimately causing erratic idling and occasional engine stalling Before proceeding with IAC valve replacement, I strongly recommend a thorough inspection of the air intake system, including the throttle body and intake manifold A visual assessment for excessive carbon buildup is crucial; if present, cleaning may resolve the issue Furthermore, could you provide the specific error code retrieved from the engine control unit This information may offer further insight into the root cause of the problem

Thanks for the detailed response The error code is P0505 Where exactly should I be looking for carbon buildup in the air intake I'm not super familiar with the layout of the engine, but I can probably find my way around with some guidance

Error code P0505 corroborates the suspicion of an idle air control system malfunction, further implicating the IAC valve or related components As for your inquiry regarding carbon deposit localization, focus your inspection on the following areas: the throttle body bore and plate; the intake manifold runner inlets, particularly those closest to the throttle body; and the IAC valve itself, if accessible In some vehicle configurations, the IAC valve is integrated into the throttle body assembly If the deposits are substantial and prove resistant to manual removal, chemical induction cleaning by a trained technician may be warranted Given your acknowledged unfamiliarity with the engine's architecture, I would advise consulting a certified Mercedes-Benz technician for a comprehensive diagnostic assessment and appropriate remedial measures While DIY cleaning is feasible, improper techniques or aggressive solvents can inflict damage upon sensitive components, potentially exacerbating the problem It may be best to bring it in to the shop

Thanks again for the help I took it to a workshop The mechanic confirmed it was the air intake being heavily contaminated and the IAC valve They cleaned everything up and replaced the valve Cost me about 425€, but the engine is running smoothly now No more stalling