Audi S1 Starting Issues: Rough Idle & Engine Stalls

Had a similar starting issue with my 2012 Audi A1 last year. Have some experience with basic car maintenance, but this one needed professional help. The symptoms were exactly like yours, intermittent starting problems and occasional rough running. Initially thought it was the ignition coil or starter motor, but after taking it to the workshop, they diagnosed a blown fuse in the ignition circuit. The repair was straightforward, they replaced the faulty fuse and checked the surrounding wiring. Total cost was 52 Euro including diagnostic time. Since the fix, starting has been perfect with no issues. However, these symptoms can point to multiple problems in the starting system. To help diagnose more accurately, could you share: Does the dashboard light up normally when you turn the key? Do you hear any clicking sound when attempting to start? Has the check engine light come on? Any recent electrical upgrades or work done? The ignition system is complex and similar symptoms can come from various components, from a simple fuse to more serious issues with the ignition switch or starter motor. Best to rule out the simple fixes first.

Last service was at 45000 KM in August, car currently at 51234 KM. Thanks for sharing your experience. Had all electrical system components checked and noticed the dashboard indeed flickers slightly when turning the key. No clicking sounds present, but the check engine light started appearing intermittently last week. Previous owner installed an aftermarket alarm system which might be interfering with the car electronics. The ignition switch itself feels a bit loose compared to when I first got the car, and there is sometimes a delay between key turn and engine response. Worth noting the issue gets worse in damp weather, which makes me suspect its an electrical connection problem rather than a mechanical fault.

Based on your additional details, especially the loose ignition switch and weather sensitivity, I am now even more convinced this is different from my fuse issue. Your symptoms strongly point toward an electrical connection problem, likely compounded by that aftermarket alarm system. After my fuse replacement, I also had the workshop do a full electrical system check because I was concerned about potential damage to other components. A key learning was that aftermarket installations can create unexpected interference with car electronics, particularly the engine start systems. The flickering dashboard combined with the weather sensitivity suggests possible corrosion or loose connections in the ignition circuit. The starting issue is likely more complex than my simple fuse problem. Recommend getting three things checked: 1. Complete inspection of the ignition switch wiring 2. Professional review of the alarm system installation 3. Diagnostic scan focused on the intermittent check engine light My total diagnostic costs ran to about 150 Euro, but it was worth it to prevent potentially bigger issues with the starter motor or car electronics down the line. The intermittent nature of your problem matches classic symptoms of deteriorating electrical connections. Mind sharing if the aftermarket alarm was installed by a certified shop? This could help determine if its a potential warranty issue.

Thanks for the detailed analysis. You are right that this seems more complex than a simple fuse issue. And yes, the aftermarket alarm was installed by a local car audio shop, not an authorized dealership. Got their contact details and service documentation, but the 1-year warranty expired last month. The check engine light pattern is definitely concerning. It usually comes on right after those difficult starts, then disappears once the engine is running smoothly. After your advice, I monitored the car ignition behavior more closely and noticed the engine start issues are most frequent during morning starts when theres heavy dew. Getting it booked in next week for a full diagnostic scan and electrical system check. Will have them focus on the ignition switch, alarm system integration, and those potentially corroded connections you mentioned. While not cheap, it makes sense to get a proper diagnosis before the problems get worse or leave me stranded somewhere. Will update once I have the workshop report. Really appreciate the time you took to analyze this, helped me better understand what to look out for and discuss with the technicians.