Golf Engine Stalls: EVAP System Valve Problems Revealed

As someone with moderate automotive repair experience, I had a very similar issue with my 2019 Golf GTI where the check engine light kept coming on and the engine would stall at idle. After some troubleshooting, it turned out several EVAP system hoses were completely clogged. The workshop found the ventilation lines running from the fuel tank to the EVAP system were blocked with debris, causing pressure buildup. The entire repair, including diagnosis and hose replacement, cost 175€ and took about 3 hours to complete. Since the fix, the engine light has stayed off and idle performance returned to normal. Before offering more specific advice, could you share: Have you checked if the gas cap is properly tightened? Are there any other warning lights on the dash? Does the stalling happen more frequently after refueling? Have you had any recent fuel system or emissions work done? These details would help determine if your issue matches what I experienced and whether you might need similar repairs.

Thanks for the feedback. Since my last service 2 months ago, Ive confirmed the gas cap is tight and secure. The only warning light present is the check engine light, no other dash indicators. The stalling occurs out of nowhere, not just after refueling. The purge valve makes an unusual clicking sound during idle, which I noticed recently. Worth mentioning the last diagnostic scan showed a P0456 code related to the EVAP system. This could help narrow down the potential fixes before I take it in.

Thanks for those extra details. On my Golf, I also experienced that distinct clicking from the purge valve before the full repair. The P0456 code you mentioned is exactly what I got, it typically indicates a small EVAP system leak, which matches the symptoms. Before replacing the hoses in my case, the mechanic performed a smoke test of the EVAP system which revealed multiple small leaks in the vent lines near the fuel tank. The pressure sensor readings were also irregular, suggesting the system wasnt maintaining proper pressure. Given the similarities to my experience (same clicking sound, identical error code), its likely you have the same underlying issue with the EVAP system components. The unusual stalling without connection to refueling actually strengthens this theory, as it suggests a system-wide pressure regulation problem rather than just a gas cap or single valve issue. While the ventilation valve was initially suspected in my case, the real culprit was the deteriorated hoses. When scheduling your repair, make sure they plan for a complete EVAP system inspection, including pressure testing. This will help avoid replacing parts unnecessarily. Would you mind checking if you notice any fuel smell around the car? That was another symptom I experienced that helped confirm the diagnosis.

Thanks for the detailed response. Yes, I actually do notice a faint fuel smell, especially when parked in my garage overnight. Based on your experience, I'll definitely request a complete EVAP system inspection including the pressure test when I take it in. The clicking purge valve combined with the P0456 code and similar symptoms to your case makes me more confident about the potential issue. The tank ventilation system problems you described match what I'm experiencing, particularly the unusual stalling and check engine light behavior. I'll make sure to mention these specific symptoms and the smoke test you suggested when I schedule the repair. If the fix is similar to yours, about 3 hours of labor and roughly 175€, that seems reasonable for peace of mind and proper engine operation. I appreciate you sharing your repair experience. It helps knowing someone else has successfully resolved such similar EVAP system issues. I'll update once I get the car checked out and find out if the diagnosis matches your case.