Audi Q5 Hybrid Stalling: EVAP System Problems Fixed

Having faced a similar issue with my 2019 Audi Q3 Hybrid, I can share my experience. With some automotive repair background, I encountered comparable symptoms, stalling at idle and an activated check engine light. Initially, I also checked the gas cap and basic sensor readings. However, the problem turned out to be clogged hoses in the EVAP system. The workshop diagnosed a blockage that was preventing proper vapor flow, causing the stalling issues. The repair cost was 175 Euro, including diagnostics and cleaning of the affected components. The fix resolved both the stalling and the engine light issues completely. Before suggesting more specific solutions, could you provide: Current mileage on your Q5, Any other warning lights or messages, Whether the stalling occurs more frequently when the fuel tank is at a specific level, If you notice any fuel smell This information would help determine if your issue matches what I experienced or if it might be something different in the EVAP system.

Last service was at 75000 km, currently at 78321 km. After investigating further, I noticed the stalling gets worse when the tank is nearly full. No fuel smell detected, and the only warning is the check engine light. The purge valve makes a clicking sound when the engine starts, which might indicate an emission system problem. I will try disconnecting the battery for 30 minutes to reset the system before taking it to a workshop. The vehicle has been otherwise reliable with regular maintenance.

Thanks for providing those details. Based on what you describe, your symptoms are nearly identical to what I experienced with my Q3, particularly the stalling when the fuel tank is full and the clicking purge valve sound. After my initial diagnosis with the clogged hoses, I also discovered the tank ventilation system was not functioning properly due to a faulty purge valve. The clicking sound is a clear indicator of this, the valve should operate smoothly without audible clicking. A battery reset might temporarily clear the check engine light, but in my case, it returned within 50km of driving. The root cause needs addressing. The purge valve replacement on my vehicle cost 320 Euro including labor, which resolved both the stalling and emission system issues permanently. Given your mileage is similar to when my issue occurred (around 80000 km), this appears to be a common wear point for this component in our engine family. While waiting for the workshop appointment, try to keep the fuel tank below 3/4 full to minimize the stalling episodes. Would you mind updating us on whether the battery reset helps? This information could benefit others facing similar automotive repair challenges with their tank ventilation systems.

Thanks for the input. Quick update: The battery reset didnt help, the check engine light came back after about 30km of driving, just as mentioned. The stalling is still happening when the tank is full, so I scheduled a workshop appointment for next week. Based on the feedback here and the clicking noise from the purge valve, I am fairly confident its an EVAP system issue. The 320 Euro estimate for the repair seems reasonable compared to other quotes I got. Will keep the fuel tank below 3/4 full until then as suggested. Since the pressure sensor readings are normal and theres no fuel smell, I feel better knowing its likely just the purge valve rather than a more serious fuel tank problem. Will post an update after the repair is done for others who might run into similar issues with their hybrids.