VW Tiguan Glow Plug Issues, Warning Signs & Solutions

Had a very similar issue on my 2009 VW Touran diesel. As someone with some experience working on cars, I initially thought it might be a simple glow plug replacement, but it turned out to be more complex. The engine misfire symptoms and warning lights were almost identical to what you describe. After experiencing vehicle stalling a couple times, I took it to a workshop. The diagnostic revealed a faulty connection between the control unit and the glow plug wiring harness. The cable insulation had worn down, causing intermittent connections. The repair was straightforward, they replaced the damaged wiring and connectors, costing 95€. Since the fix, no more warning lights or smoke issues. The car runs perfectly now. Would strongly advise not driving it longer than necessary. A faulty glow plug system can cause starting problems and potentially damage your diesel engine over time. To provide more specific advice, could you share: Any unusual sounds during startup? Does the problem get worse in cold weather? Have you noticed decreased fuel efficiency? When was your last full engine diagnostic check?

Thanks for sharing your experience. Latest service was at 58000km, about 6 weeks ago. The unusual sounds started right after cold starts and yes, fuel consumption has increased noticeably. The vehicle stalling occurs more frequently during cold mornings, especially after short trips. The heating element problems seem to match my situation exactly. Had the diagnostic test done yesterday which pointed to the glow plug control module, but wanted to confirm if this matches real-world experiences before committing to the repair. The quoted price for parts and labor is 280€. The smoke during acceleration has gotten worse over the past week, and the engine misfire is now more noticeable, so planning to book the repair soon rather than risk further damage to the diesel engine.

Your symptoms exactly mirror what I experienced, the increased smoke, cold start issues, and that telltale vehicle stalling during cold mornings. The 280€ quote seems reasonable considering the parts and labor involved. In my case, I initially hesitated on the repair too, but the deteriorating performance convinced me to act. The glow plug diagnostic test results matching the control module failure makes perfect sense. After my repair, I learned that when these control units start failing, they often cause cascading issues with the heating element system, leading to those morning cold start problems you described. Since you mentioned the smoke is getting worse and fuel consumption has increased, I would not delay the repair. My mechanic explained that running the engine with faulty glow plugs can lead to incomplete combustion, which explains the smoke and could potentially cause more expensive damage. One tip from my experience: have them check all the glow plugs while they are replacing the control module. In my case, one plug was also failing, and replacing both at once saved on labor costs. The improvement in performance after the repair was significant, better cold starts, no more smoke, and fuel consumption returned to normal. The engine also runs much smoother now, especially during those cold morning starts.

Your symptoms exactly mirror what I experienced, increased smoke, cold start problems, and engine misfires during cold mornings. Based on your feedback and my recent diagnostic results, I will proceed with the repair next week. The 280€ price seems fair, especially compared to potential issues from delaying the fix. Car maintenance is clearly needed soon since my diesel engine symptoms are worsening. The smoke during acceleration and poor fuel economy are concerning signs that the heating element system needs immediate attention. The vehicle stalling during morning drives has become more frequent, making me nervous about daily commuting. Going to ask them to inspect all glow plugs while replacing the control module, since multiple components in the preheating system could be affected. This approach should save on future labor costs if other parts are wearing out. Thanks for confirming that the diagnostic test results align with real-world experiences. Hearing about the improved performance after your repair gives me confidence this will resolve my issues. Will update once the work is completed.