VW Tiguan Glow Plug Warning, Fix Guide & Tips

Had a similar issue on my 2013 VW Passat TDI. The check engine light came on with the same glow plug warning symptoms. Initial cold starts became increasingly difficult, especially during cold weather, causing rough idle and poor fuel efficiency. The diagnostic revealed two failed glow plugs and a damaged control module. This is a common issue on TDI engines after extended use. Its not just about replacing the defective glow plug, the entire system needs proper testing because one failure often leads to others. The repair turned out to be more involved than initially expected. The mechanic found corrosion in the wiring harness connecting to the glow plugs, which was causing intermittent electrical issues. The complete repair included replacing all four glow plugs as a preventive measure, plus the control module and harness. While its a serious repair requiring specific diagnostic equipment, its not catastrophic to the engine if addressed promptly. Important to note that continuing to drive with faulty glow plugs can lead to starting problems and potential damage to other components. Recommend finding a shop specializing in VW diesels, as they will have the proper diagnostic tools and experience with these specific systems.

Thanks for sharing your experience. Those symptoms match exactly what happened to my Tiguan last winter. How much did you end up paying for the complete repair? Would be helpful to know for comparison since my local shop quoted quite high. I noticed you had the wiring harness replaced too, this wasnt initially suggested in my case but now Im wondering if I should have it checked. Have you had any engine combustion issues or check engine warnings since the repair was done?

Thanks for asking about the repair costs. After getting the glow plug system fixed recently, I can confirm it cost me 440€ for the complete repair. The price covered labor and replacing the defective glow plug. This actually turned out to be more reasonable than initially expected, especially since the engine combustion is now running perfectly. Since the repair, my diesel engine has performed flawlessly, no more check engine lights or cold start issues. The fuel efficiency has actually improved noticeably. While my mechanic checked the wiring harness during the inspection, it was in good condition and didnt require replacement in my case. The key difference between our situations might be that I caught the issue early, before it could cause any additional problems. If your wiring harness wasnt checked, it might be worth having it inspected just to be safe, as faulty wiring can lead to similar symptoms even with new glow plugs.

Thanks for the input. After getting several quotes, I finally had the repair done at a diesel specialist shop with good reviews. Total cost came to 680€, which included replacing two faulty glow plugs, the control module, and fixing some corroded wiring in the harness they discovered during inspection. The engine combustion is now perfect and cold starts are smooth again. No more check engine warnings or preheating indicator issues. The mechanic showed me the old parts and explained everything clearly, which was refreshing after my previous bad experience. What really convinced me to go with this shop was their thorough diagnostic approach. Instead of just replacing parts, they tested the entire glow plug system and found the root cause. The fuel efficiency has definitely improved since the repair. For anyone facing similar issues, its worth paying a bit more for a proper diagnosis rather than just replacing parts hoping to fix the problem. Lesson learned from my previous attempt at getting it fixed.