VW Eos Glow Plug Light Stays On, Real Owner Fixes

I had a similar glow plug issue with my 2012 VW Passat diesel engine last winter. The check engine light and preheat indicator were constantly illuminated, causing rough idle problems especially during cold starts. Initially thought it was just one defective glow plug, but diagnostic testing revealed two were failing and the glow plug control module was also damaged. This explained the continuous preheating light. The issue was causing poor fuel efficiency and incomplete combustion. The repair involved replacing all four glow plugs as a set (recommended practice) and the control module. This was definitely a serious repair that required specialized diagnostic equipment to properly identify which components were faulty. If left unaddressed, it can lead to starting problems and potential engine damage. While generic glow plugs are available, using OEM parts is crucial for these diesel engine components to ensure proper function and longevity. The job took about 3 hours since accessing the glow plugs required removing several components to gain proper clearance. Since the repair, cold starting has been perfect and the engine runs smoothly without any warning lights.

Thanks for sharing your experience. Those diesel engine problems with the glow plugs sound exactly like what I am dealing with. My engine light came on about a week ago showing the same symptoms. Did replacing the control module along with the glow plugs completely solve your starting issues? Can you remember roughly what you paid for parts and labor? Just want to get an idea before heading to the shop. Also curious if youve had any other problems pop up since the repair was done?

Finally got around to updating this thread. Yes, replacing both the glow plugs and control module completely resolved the starting issues with my diesel car. Total cost was 440€ for the complete fix, including parts and labor. The engine misfire and rough starts are completely gone since the repair. The mechanic confirmed it was definitely a glow plug failure causing the problems. Engine combustion is now perfect, especially during cold starts. The repair has held up great for several months now with no new issues appearing. Fuel efficiency actually improved noticeably after fixing the faulty glow plugs. The investment was worth it to prevent potential long-term engine damage. Having a properly functioning preheating system is crucial for these diesel engines, especially during colder weather. I recommend getting it fixed soon to avoid more serious problems developing.

Had my VW checked out yesterday after reading these responses. Turns out my situation was nearly identical, faulty glow plugs and control module. Got it all fixed for 460€ which seems fair based on other experiences shared here. The mechanic was actually quite transparent and showed me the worn glow plugs after removing them. The diesel engine runs so much better now, with perfect cold starts and no more rough idle issues. Even noticed slightly better fuel efficiency on my drive home. Really glad I asked here first, helped me understand the issue and typical repair costs before going in. Saved me from getting quoted inflated prices or unnecessary work. Engine combustion is smooth now and all warning lights are finally off. Definitely feel better about the whole repair experience this time around.