Audi SQ7 Glow Plug Warning Light Won't Turn Off

Had a similar issue on my Audi Q7 3.0 TDI (2014). The glow plug warning light stayed on permanently, causing rough idle and poor fuel efficiency during cold starts. The engine light indicated multiple glow plug failures. One faulty glow plug can usually be managed, but multiple failures require immediate attention as they affect engine combustion and can lead to starting problems, especially in cold weather. The repair needed complete glow plug replacement since testing showed three of them were defective. While the glow plugs were accessible, the mechanic also checked the control module and wiring harness for potential damage. The process took about 4 hours due to careful removal of old plugs to prevent cylinder head thread damage. This is considered a moderate to serious issue because neglecting it can lead to: Failed cold starts, Increased fuel consumption, Potential damage to other engine components, Higher emissions, Reduced engine performance Recommend finding a certified diesel specialist for this repair, as proper torque settings and specific tools are required. Also worth checking if your vehicle is still under warranty as this could be a manufacturing defect given the low mileage.

Thanks for the detailed explanation of your glow plug experience. Your description of the multiple failed plugs and engine misfire symptoms matches what I am seeing. My diesel engine has been showing similar starting issues lately. Did you remember roughly how much the total repair cost? Also curious if you have had any related problems since the fix, particularly with the engine light or fuel efficiency? I want to make sure I budget correctly and address any potential connected issues while the car is in for service.

Good news to report after getting the glow plug issue fixed on my Q7. The total repair came to 440 Euro, which covered replacement of the defective glow plugs and necessary testing. Since the repair, the engine light has stayed off and cold starts are working perfectly. The fuel efficiency has actually improved noticeably compared to when the glow plugs were failing. The engine misfire issues completely disappeared after the fix. Its been several months now with no related problems or warning lights returning. A certified diesel specialist handled the work and they were right to recommend replacing all affected plugs at once rather than just the most damaged ones. This thorough approach seems to have prevented any recurring issues. The investment was worth it to restore proper engine function and prevent potential long-term damage. Check engine warnings havent returned since the repair, confirming they addressed the root cause correctly.

Thanks for the feedback. I finally got my diesel car fixed last week and wanted to share my experience. Took it to a certified specialist who actually found 4 faulty glow plugs. The cold start issues were worse than I initially thought. Total cost came to 520 Euro including diagnostic testing and replacement of all glow plugs. More expensive than expected but the fuel efficiency improvement made it worthwhile. The engine combustion is much smoother now and the warning lights are completely gone. The new shop did a thorough job testing the control module and wiring while they had it open. Much better experience than my previous mechanic. Cold starts are perfect now, even on chilly mornings. Really glad I addressed this when I did, the specialist mentioned the failing plugs could have eventually caused more serious engine damage. Three weeks since the repair and everything is running great with no warning lights or starting issues.