VW Jetta Glow Plug Light Stays On, Fix Guide Needed

Had the same glow plug issue with my 2011 VW Passat TDI. The check engine light appeared along with constant preheat warning. Engine misfire and rough idle were most noticeable during cold starts. Diagnosis revealed two faulty glow plugs and a damaged wiring harness. The repair involved replacing all four glow plugs as a set, plus the harness. This is actually a serious issue that needs prompt attention since bad glow plugs can lead to starting problems, poor fuel efficiency, and potential engine damage if left unchecked. The job took about 3 hours at the shop. Make sure they check the wiring harness, this is often overlooked but can cause the same symptoms if damaged. Getting all plugs replaced at once is recommended since they typically wear at similar rates. The symptoms you describe match exactly what I experienced. Get it fixed soon to avoid more extensive repairs later. Ask for a detailed inspection report and ensure they test all glow plugs individually before and after replacement.

Thanks for sharing your experience with the glow plug repair. My check engine light also came on recently with similar cold start issues on my Jetta. The symptoms you described sound identical to what I went through. Did you remember roughly how much the total repair cost? Also curious if you had any related issues pop up since getting it fixed? Asking because I need to mentally prepare for the bill and want to make sure I address everything while the car is in the shop.

Just got back from having this exact repair done on my Passat TDI. The total came to 440€ including parts and labor. The glow plug failure was definitely the root cause, and since the repair my diesel engine starts perfectly, even in cold weather. No more rough idle or check engine light issues. The mechanic confirmed all glow plugs were tested and replaced as a set, which is standard practice. The cold start problems completely disappeared after the fix. Its been a few months now and no related problems have surfaced. The engine runs smooth and the warning lights have stayed off. You are smart to address this promptly. Faulty glow plugs can lead to starting problems and poor performance if ignored. While not a cheap repair, its worth getting it done right to prevent more expensive issues down the road.

Finally got my Jetta back from the shop today after dealing with that glow plug problem. The whole repair came to 470€, slightly more than expected because they found a damaged wiring harness that needed replacing along with the glow plugs. The diesel car starts like new now, no more rough idle or warning lights. The mechanic showed me the old glow plugs and they were pretty worn. He did a thorough job testing everything before and after the repair. What a relief to have this fixed. The check engine light is finally off and cold starts are smooth again. Definitely worth getting it done properly rather than letting it get worse. Thanks again for the advice, it helped me know what to expect at the shop.