Jetta Stalling at Idle: Faulty EVAP Valve Symptoms

Had similar issues with my 2004 VW Passat. The symptoms match a clogged purge valve in the EVAP system. When the tank ventilation system gets blocked, it creates irregular fuel pressure, causing those exact stalling problems at idle. Took three days at the garage to properly diagnose. The main issue was debris accumulation in the EVAP lines, blocking proper fuel tank ventilation. The pressure sensor was also giving false readings because of this blockage. Required cleaning of the entire EVAP system and replacement of the purge valve. Important to note, this is not just an inconvenience issue. A malfunctioning EVAP system can lead to fuel delivery problems and potential engine damage if left unaddressed. The gas cap should also be checked, as a faulty seal can contribute to similar symptoms. The automotive repair involved removing multiple components to access the system. Suggest having a professional mechanic check the pressure readings and inspect the purge valve. Running the engine with these symptoms could cause additional problems. These issues are common in VWs of that generation, especially when regular maintenance has been delayed.

Thanks for sharing your experience. I had almost identical symptoms on my Jetta last year. The check engine light kept coming on and the car would stall at stops. My purge valve was completely blocked and needed replacement along with a thorough cleaning of the fuel tank ventilation system. Did you track how much you ended up paying for the full repair? Also wondering if youve had any recurring EVAP system problems since getting it fixed?

Just got the final bill last week, the repair came to 175€ for cleaning out the clogged hoses and fixing the tank ventilation valve malfunction. Since seeing the mechanic, the emission system has been working perfectly. No more check engine lights or stalling issues at idle. The thorough cleaning of the EVAP system components really made the difference. The purge valve is functioning correctly now, and the fuel tank pressure stays properly regulated. Its been about 3 months of trouble-free driving. For anyone facing similar problems, getting the complete system checked is worth the investment. A properly working EVAP system prevents both performance issues and potential emission control problems. Just make sure to have regular maintenance done to prevent debris buildup in those ventilation lines. The repair cost was reasonable considering the diagnostic work needed to pinpoint the exact issue in the emission system. Much better than risking more expensive engine repairs down the road.

After getting your feedback, I took my Jetta to a different mechanic who specializes in VW repairs. The automotive repair was completed in just one day and cost 220€ total. The technician found a completely clogged purge valve causing all my fuel tank ventilation issues. The check engine light hasnt come back since the fix two weeks ago. My car now idles smoothly at traffic lights and the emission system seems to be working perfectly. The mechanic also showed me the old valve, it was packed with carbon deposits that were blocking proper ventilation flow. This experience taught me to address these symptoms early. A simple tank ventilation problem can lead to bigger issues if left unfixed. Really glad I caught it before any serious engine damage occurred. Much better experience with this shop compared to my previous repair attempts.