Audi Glow Plug Warning Signals Engine System Alert

As a DIY enthusiast with some mechanical experience, I had a similar issue with my 2019 Audi A6 diesel engine. The engine light and glow plug indicator remained illuminated, causing concern about cold start performance. After diagnostic testing, it turned out one glow plug was defective, triggering the warning lights. The repair involved replacing the faulty glow plug and running a system check to ensure proper diesel engine operation. Total cost including parts and labor was 440 Euro. A few things to consider with glow plug issues: Individual plug failure is common and less expensive to fix, Complete preheating system issues are more complex, Ignoring the problem can lead to difficult cold starts and poor combustion Before proceeding with repairs, could you share: Current mileage on your A8, When you first noticed the warning lights, Any changes in starting behavior or engine performance, Whether diagnostic codes have been read This information would help determine if your situation matches what I encountered and provide more specific guidance. Even with warning lights, continue using the vehicle but monitor cold start behavior closely. Having it checked soon is advisable to prevent potential starting issues, especially in colder weather.

Last serviced at 121180 KM about 2 weeks ago and had no issues reported then. After reading through the comments, I checked with my OBD reader and got error code P0674 which confirms cylinder 4 glow plug malfunction. The engine misfire occurs mainly during cold starts. Will get it checked at a workshop since the car is running fine otherwise. Thanks for the detailed cost breakdown and guidance offered. Knowing its likely just a single glow plug gives me some peace of mind about the repair scope.

Thanks for the update and diagnostic info. The P0674 code on your A8 matches exactly what I experienced, its a clear indicator of cylinder 4 glow plug failure, just like what happened on my A6. The rough idle and engine misfire during cold start that youre experiencing are typical symptoms. My repair cost reference of 440 Euro should be close to what youll see, especially since its also just a single glow plug issue. Good call on planning to get it fixed soon. While the engine runs okay once warmed up, a faulty glow plug can cause incomplete diesel combustion during cold starts, potentially leading to carbon buildup over time. Since you mentioned having an OBD reader, keep monitoring for any additional codes. In my case, it stayed as an isolated glow plug issue, but its smart to watch for related problems developing in the preheating system.

Thanks to everyone for the helpful feedback. Just wanted to close the loop, took the A8 to a workshop yesterday and as suspected, it was just the cylinder 4 glow plug that needed replacement. Final cost came to 410 Euro which was even slightly less than expected. The check engine light is now off and the diesel engine starts perfectly, even during cold start conditions. No more rough idle issues either. The mechanic also checked the other glow plugs and confirmed they are all functioning properly, so hopefully wont have any similar problems for a while. Really appreciate all the guidance which helped me understand the issue before taking it in.