VW Lupo Stalling: Bad Ignition Coil Warning Signs

After seeing your post, I had very similar issues with my 2003 VW Polo. As someone with some repair experience working on VWs, the symptoms you describe match exactly what I encountered, rough idle, stalling, and jerking during acceleration. The check engine light was also constantly illuminated. My workshop ran vehicle diagnostics and found a faulty connection between the coil pack and wiring harness. The cable insulation had worn through, causing intermittent connection issues. They fixed the wiring and connections for 95€, which resolved all symptoms completely. However, your case might be different since coil failure can manifest in several ways. Before suggesting specific repairs, could you share: Current mileage on your Lupo, When was the last spark plug replacement, Does the issue get worse when the engine is hot, Are there any specific conditions when the stalling occurs more frequently This information would help determine if you are dealing with a simple connection issue like mine or if there might be a failing coil pack that needs replacement. The good news is that these ignition system problems are usually straightforward to diagnose and fix once properly identified.

Last service was 3 months ago at 62000km, and now showing 63829km on the clock. Thanks for sharing your experience, those symptoms match mine exactly. The stalling definitely gets worse when the engine is hot, particularly in stop-start traffic. I checked the spark plugs during the last service and they looked fine, but maybe I should inspect the wiring harness based on your feedback. The engine hesitation is most noticeable first thing in the morning. I will take your advice and have the connections checked before jumping to conclusions about complete coil failure. Did your repair shop do a specific test to identify the wiring issue? Curious about the diagnostic process that led them to find the worn insulation.

Based on those additional details about hot engine stalling and morning hesitation, this sounds even more similar to what I experienced with my Polo. The diagnostic process at my shop involved using a specialized scanner that monitored ignition coil signals while the engine was running at different temperatures. The most telling sign in my case, and it matches your symptoms, was how the problems got worse with heat. This often indicates either a failing ignition coil or damaged wiring that shorts out as components expand with temperature. The morning hesitation is also typical of connection issues, as overnight condensation can affect poor connections. My repair actually started with them testing each ignition coil independently. They found inconsistent readings and traced it back to the wiring. The check engine light would flicker during their tests, which helped pinpoint where the connection was failing. Have your shop do a hot-cold cycle test specifically focusing on the ignition system. In my case, running the engine until fully warm made the problem much more obvious for diagnosis. Given your mileage is similar to when I had issues, and considering the identical symptoms, I strongly suspect you will find either wiring damage or a weakening coil pack. The morning issues you mention make me lean more toward checking those connections first, just like in my case. The repair was much simpler and cheaper than replacing the entire ignition coil.

Thanks for the detailed explanation and test recommendations. The hot-cold cycle test seems like a smart diagnostic approach since my issues are so temperature dependent. My mechanic mentioned doing a simple visual inspection first, but I will specifically request they check the wiring connections using their diagnostic equipment as you suggested. Just to add another observation, I noticed the check engine light actually flickers occasionally during acceleration, similar to what your shop found during testing. This really does point toward a connection issue rather than complete ignition coil failure. And considering the morning engine hesitation gets better as things warm up, damaged wiring makes more sense than a bad coil pack. I will book it in next week and have them focus on the ignition system connections first. The 95€ repair cost you mentioned is much more appealing than replacing parts unnecessarily. Will update once I know more about what they find during the hot-cold testing.