VW Polo Throttle Issues Impact Starting & Fuel Economy

Had the exact same problems on my 2018 VW Golf diesel. The car throttle was acting weird, especially during cold starts, and fuel economy took a hit. With basic experience working on cars, I first thought it was the throttle body causing issues. Took it to my regular workshop and their diagnostic revealed a defective accelerator pedal module, not the throttle position sensor as initially suspected. The engine throttle response improved dramatically after replacing the module. Total repair cost was 205€ including parts and labor. The symptoms you describe match perfectly, inconsistent throttle response and starting issues are classic signs of either a bad pedal module or air intake problems. The workshop ran a full diagnostic on the engine throttle system to pinpoint the exact cause. To help diagnose your specific case, could you share: Any warning lights on the dash? Does the engine rev smoothly when pressing the accelerator? When did these symptoms first appear? Have you noticed any changes in engine sound? These details would help determine if you are facing the same issue I had. The accelerator pedal module is often overlooked when diagnosing throttle-related problems.

Thanks for sharing your experience. After my last service at 85000km, I started noticing these throttle response issues more frequently. You raise good points about the pedal module. No warning lights showing, but the engine does hesitate slightly when accelerating from idle. The throttle body definitely feels less responsive compared to before. I will get the air intake system checked as well since poor fuel efficiency could also point to restricted airflow. I did some basic throttle cleaning myself last month which helped temporarily, but the symptoms returned within a week. Will have the workshop do a proper diagnostic on both the pedal module and throttle position sensor to identify the root cause.

Thanks for the additional details about your VW Polo. Based on your symptoms and my experience with the same issue, temporary improvement after throttle cleaning strongly suggests carbon buildup in the air intake system rather than a pedal module failure like I had. When my throttle cleaning only provided short-term relief, it turned out there was significant carbon accumulation affecting proper engine idle and throttle response. The restricted airflow was causing the inconsistent acceleration you described. A professional throttle cleaning service might be worth considering before replacing parts. My mechanic performed a thorough air intake system cleaning that resolved similar symptoms for about 150€. They used specialized equipment to clean both the throttle body and intake manifold. The engine idle should stabilize and throttle response improve significantly after proper cleaning. If issues persist, then investigating the pedal module or throttle position sensor would be the next logical step. Since you mentioned no warning lights, this further supports air intake restriction being the likely cause rather than an electronic throttle control issue.

Thanks for all the input about the throttle cleaning and potential causes. After reading about similar cases, I am convinced the air intake system needs professional attention. The correlation between the temporary fix from my basic throttle cleaning and the returning symptoms matches what others experienced with carbon buildup. I have scheduled a full diagnostic next week where they will check both the engine throttle system and air intake components. The mechanic mentioned they have specialized equipment for thorough throttle body cleaning, which sounds like a good starting point given the symptoms. The lack of warning lights and the temporary improvement from cleaning really points toward carbon deposits rather than control valve issues. Will have them inspect the pedal module as well just to be thorough, but focusing first on a professional throttle cleaning service makes the most sense. I appreciate the detailed feedback about costs and diagnostic steps. Having this information helps set realistic expectations for the repair process. Will update once I know the actual cause and required fixes.