VW Polo Stalling: Fuel Tank Ventilation System Alert

Had nearly identical issues on my 2016 VW Golf last year. The symptoms match exactly what I experienced, rough idle, stalling, and system failure warnings through the check engine light. After some basic diagnostic work, my workshop found the activated charcoal filter in the emission control system was defective. This component is crucial for the fuel tank ventilation and leak detection system. When it fails, it can cause exactly these stalling issues, especially at idle. The repair took about 2 hours and cost 275€ total, including parts and labor. Since the fix, fuel efficiency returned to normal and no more stalling issues. However, to provide more specific guidance: What engine size does your Polo have? Have you noticed any fuel smell? Does the check engine light flash or stay constant? How many kilometers on the odometer? These details would help confirm if your issue matches what I experienced. The charcoal filter issue is fairly common on VW models from this era, but its always best to get a proper diagnosis since similar symptoms can have different causes. Make sure the workshop specifically checks the entire fuel tank ventilation system, not just the purge valve. Sometimes mechanics focus only on the valve when the filter is the actual culprit.

Last service was done at 95000km and I am also experiencing similar stalling issues when the fuel tank is less than half full. The check engine light stays constant, no flashing. No noticeable fuel smell around the car. Engine size is 1.0L TSI. I checked the fuel tank cap and it seems properly sealed. Will have the workshop check the charcoal filter and entire ventilation system. Really hoping its just the filter and not a more complex fuel system failure. Thanks for sharing your repair costs, helps set expectations for the upcoming service visit.

Thanks for those additional details. Yes, that matches even closer to what I experienced with my Golf. The constant check engine light combined with stalling at low fuel levels strongly points to the charcoal filter issue, especially since no fuel smell is present. The 1.0L TSI has actually had several documented cases of this exact problem. In my case, the workshop also found that the leak detection pump near the charcoal filter was showing signs of wear, but it wasnt critical for replacement yet. The fuel tank pressure sensor readings were fluctuating on my diagnostic scan, which is a typical indicator of a failing charcoal filter in the ventilation system. My mechanic mentioned that these components often wear out around the 90-100k kilometer mark on these engines. One thing I learned from my repair, make sure they also inspect the purge valve electrical connections while the system is apart. Mine had some minor corrosion that they cleaned up during the filter replacement, which helped ensure the new parts worked properly. The repair cost should be similar to what I paid, possibly even less since the Polo parts are usually a bit cheaper than Golf components. The whole job took less than a day at the workshop.

Thanks for your detailed feedback. You really helped narrow down the likely cause. The constant check engine light and stalling issues when the tank is low match my 1.0L TSI symptoms exactly. Its good to know the charcoal filter is a common wear item around my mileage. I will definitely have them check both the leak detection pump and purge valve connections during the inspection. Very helpful to know about the electrical connection cleaning too, will make sure to mention that specifically. The repair cost estimate gives me a good baseline for budgeting. Was worried it might be a major fuel system issue, but this sounds much more manageable. Will book it in next week and have them focus on the emission control system components you mentioned. Really appreciate the thorough explanation of what to expect during the repair. Makes me feel more confident going into the workshop with this specific issue to investigate.