VW Polo Glow Plug Light Won't Turn Off

I had a similar situation with my VW Golf TDI (2004) diesel engine. The glow plug light stayed on continuously, which usually indicates problems with the pre-heating system during cold start. After scanning, I discovered one glow plug was defective. The issue got worse during winter months when the engine needed more pre-heating for proper combustion. While the car still ran, ignoring glow plug problems can lead to harder starts, increased emissions, and potential engine damage. The repair involved testing all glow plugs individually, as often when one fails others might follow soon. In my case, the glow plug control module also needed replacement since it was sending incorrect signals to the check engine system. This is a relatively common issue on these diesel engines. While not immediately critical, it should be addressed to prevent starting problems and ensure proper engine combustion. The repair is straightforward for experienced mechanics who work with diesel vehicles. The main signs that confirmed the diagnosis: Persistent glow plug warning light, Slightly rough cold starts, Stored error codes specific to glow plug circuit, Intermittent check engine light Getting all glow plugs tested is recommended even if only one shows as faulty. This preventive approach saves time and future repairs.

Thanks for sharing that detailed experience. Dealing with similar glow plug troubles on my Polo now and your explanation really lines up with the symptoms. Especially helps knowing about checking all plugs at once since they age together. Quick question, do you recall roughly how much the full repair cost in your case? Also wondering if the problem stayed fixed or if you ran into any other diesel engine issues after sorting the glow plugs? The persistent engine light and cold start hassles are quite annoying, but good to know its fixable and not necessarily a major engine problem. Just want to budget properly before heading to the shop.

After getting the glow plug system repaired, the diesel engine has been running perfectly with no more warning lights. The total repair came to 440€, which covered replacing the faulty glow plug and testing all others. The mechanic confirmed it was a straightforward glow plug failure, exactly as suspected. The engine light issue cleared up immediately after the fix, and cold starts are much smoother now. The fuel efficiency has also slightly improved since the repair. No other engine misfire or starting problems have occurred in the months since. For the price paid, it was worth fixing rather than risking more extensive diesel engine damage from continued poor starts. If you budget around 450€, that should cover a similar repair including diagnostic time and parts. These glow plug issues are common but thankfully not too expensive to resolve when caught early.

Thanks for the advice. Finally got the car checked at a repair shop yesterday. The mechanic found two faulty glow plugs and the control module needed replacement. Total repair cost was 520€, bit more than expected but worth fixing. The cold starts are way smoother now and the check engine light has completely disappeared. The diesel engine runs noticeably better, especially in the morning. Fuel efficiency seems slightly improved too, though need more time to confirm. The mechanic explained these glow plug failures are pretty common on older diesel cars. They tested all plugs as suggested and replaced the failing ones. Good call on getting everything checked at once, saved another trip to the shop later. Really glad I asked here before going in. Helped me understand the issue and avoid getting overcharged. Car runs great now, hopefully wont have any more engine misfire issues for a while.