RSQ3 Ignition Coil Failure Symptoms and Fixes

I had a similar issue with my 2019 RS3. With some experience working on cars, I recognized those classic symptoms of ignition system problems right away, the engine hesitation, rough idle, and jerking during acceleration all pointed to coil pack issues. My workshop diagnosed it as a loose connection between the ignition coil and the wiring harness. The cable connection had worked itself loose over time, causing intermittent contact. They fixed the connection and tested all spark plugs and coil packs to ensure everything was properly seated. Total cost was 95 Euro for diagnostic and repair. Before jumping to replacing coils, have you checked: How many miles are on your current spark plugs? Is the check engine light showing any specific error codes? Does the hesitation happen more during cold starts? This could also be related to spark plug condition or wiring issues rather than failed coil packs. If its just one bad connection like in my case, replacing all coils might be unnecessary. What error codes is your car showing? This would help narrow down exactly which cylinder might be affected.

My RSQ3 currently has 177631 KM and the last service was done about 3 months ago. The vehicle diagnostics showed error code P0303, pointing to cylinder 3 misfire. The engine hesitation seems worse on cold starts and improves slightly when warm. The spark plugs were replaced during the last service, which makes me think its definitely coil related. The misfire appears consistent in that specific cylinder rather than jumping between different ones.

Thanks for the additional details. Given error code P0303 and the fact your spark plugs are new, this definitely aligns with my RS3 experience. When I had a consistent cylinder-specific misfire like yours, it was indeed a faulty ignition coil. While my initial issue was just a loose connection, I later had a complete coil pack failure in cylinder 2 showing similar symptoms, rough idle, engine hesitation and the check engine light staying on. Since your misfire is isolated to cylinder 3 and the spark plugs are fresh, I would start by replacing just that specific coil. A single coil pack replacement cost me around 85 Euro including installation. Some tips from my experience: Make sure to clear the engine codes after replacement, Have the workshop verify proper seating and connection, Consider keeping the old coil as a backup if its not completely failed If other cylinders start showing similar issues later, then you might want to consider replacing the full set. But with isolated cylinder 3 misfires, starting with just that one coil is the most cost-effective approach. Have you noticed if the engine stalling gets better once the engine is fully warmed up?

Thanks for the detailed response. Yes, the stalling does improve somewhat when fully warmed up, but the misfire is still noticeable. Based on your experience and the similar symptoms, I feel more confident now about replacing just the cylinder 3 coil pack first. Since the check engine light and vehicle diagnostics are pointing specifically to that cylinder, and given that my spark plugs are new, it makes the most sense to start there rather than doing a complete coil replacement. The price point you mentioned is helpful too, was worried this might be a much more expensive fix. Will have the workshop check the connections carefully during the coil replacement since your initial problem turned out to be connection-related. Really hoping this resolves the engine hesitation and rough idle issues I've been experiencing. Will make sure they clear the codes after the repair is done.