VW Polo Diesel Throttle Issues: Fix vs Replace Guide

I had a similar issue with my 2011 VW Golf diesel last year. Having worked on several cars before, I have some experience with throttle-related problems. The symptoms you describe match what I encountered, rough engine idling, reduced power, and check engine light. Initially thought cleaning the throttle body would solve it, but the issue was actually the throttle sensor and accelerator pedal module. Took it to my regular workshop where diagnostic testing revealed faulty electronics in the accelerator pedal module affecting the throttle response. Total repair cost was 265€ including parts and labor. After replacement, the fuel efficiency improved noticeably and the rough idle completely disappeared. Before going further, could you share: Have you checked for any error codes? Does the throttle response feel delayed or jerky? Any changes in fuel consumption lately? When was the last air intake system service? Getting this info would help determine if your issue matches what I experienced with the pedal module. While cleaning the throttle body is good maintenance, electronic issues often need proper diagnosis and replacement parts.

Thanks for sharing your experience. After reading similar cases, I checked my error codes yesterday, showing P0638 which points to throttle control problems. The response delay is very noticeable, especially when accelerating. The air intake was cleaned during my last service at 119660km, but fuel consumption has increased about 15% over the last month. I also noticed some hesitation and jerky response when pressing the gas pedal, getting worse in cold weather. Since the throttle body problems affect both air flow and engine performance, I'll probably need professional diagnosis. Good to know about the potential accelerator module connection, will have them check that too when I take it in.

Thanks for the additional details. The P0638 code you mentioned is exactly what I saw on my Golf before replacing the accelerator pedal module. The cold weather sensitivity and 15% increase in fuel consumption also mirrors my experience perfectly. The jerky response and throttle delay typically indicate the system is going into limp mode to protect the engine. While the throttle body cleaning at 119660km should have helped with air flow, the electronic control issues can develop independently. When my shop did the final diagnosis, they found the throttle position sensor was sending incorrect signals, causing the ECU to limit power output. The replacement cost breakdown was: Accelerator module: 180€, Labor: 85€, Diagnostic testing included If your symptoms are this similar to what I experienced, I would strongly recommend having both the throttle body and accelerator module checked. The fuel efficiency dropped initially because the system was compensating for faulty sensor readings, but returned to normal after the repair. Keep monitoring for any changes in engine idling or performance. If the symptoms worsen, try to get it checked soon as continued operation could impact other components.

Thanks for the input. After comparing my situation with similar cases, I feel better prepared for the repair shop visit. The P0638 error code and throttle response issues definitely suggest electronic control problems rather than just dirty components. The accelerator pedal module connection makes sense given the cold weather sensitivity and increased fuel usage. Will have the shop do a complete check of both the throttle body and sensor systems. Really helpful to know about that 265€ repair cost benchmark for the accelerator module replacement. The check engine light and rough idle are definitely concerning, so I will schedule the diagnostic testing this week. Rather be proactive than risk additional engine damage from running it too long with faulty throttle control. Plus the 15% higher fuel consumption is getting expensive. Will update once I get the official diagnosis and repair completed.