Audi S8 Starting Nightmare: Ignition Switch Troubles

Having faced similar starting issues with my 2005 Audi A8 4.2L, I can relate to these symptoms. The unusual shutoffs and rough running strongly point toward ignition system problems, but not necessarily just the switch. In my case, the starting issue turned out to be a combination of failing ignition coils and a faulty crankshaft position sensor. The car electronics would sometimes fail to properly communicate between components, causing the car ignition system to misbehave. These symptoms are quite serious as they can leave you stranded without warning. The diagnosis process involved: Testing the starter motor function, Checking for fault codes, Testing ignition coil resistance, Verifying power supply to ignition components, Testing the crankshaft sensor signal Key warning signs that matched your situation: Intermittent starting problems, Engine cutting out while driving, Rough idle when engine does start, No consistent pattern to the failures This was a serious reliability issue that required immediate attention, as failing ignition components can cause further damage to the engine management system. The repair needs professional diagnostic equipment to properly identify the root cause. While checking fuses is a good start, these symptoms typically indicate deeper electrical issues in the ignition system.

I experienced pretty much the same issues with my S8. When you turn the key, it either struggled to start or would die shortly after. The dashboard lights would flicker too sometimes. Got it fixed about 4 months ago and it has been running great since. Since your symptoms match what I dealt with (unusual shutoffs, starting problems, rough running), I am curious what the final repair cost was in your case? Also, have any new issues come up since the fix? Just want to compare notes since these ignition coil and sensor problems can sometimes be related to other electrical gremlins that show up later.

After getting it properly diagnosed, the ignition switch problem turned out to be simpler than expected. The main starting issue was actually caused by a defective fuse that was disrupting power flow to the ignition system. Total repair cost came to 52 Euro for the fuse replacement and diagnostic time. The car ignition has worked flawlessly since the repair, no more unusual shutoffs or dashboard light flickering. No additional electrical problems have surfaced in the months following the fix. The key turns smoothly now and the engine starts reliably every time. Looking back, the symptoms were classic signs of an electrical fault in the ignition circuit. Having a qualified mechanic trace the issue to a blown fuse saved me from unnecessarily replacing more expensive components like ignition coils or sensors. The starting issue being resolved with just a fuse replacement was fortunate compared to what it could have been. The car electronics are all functioning normally now without any new problems developing.

Thanks for sharing my experience with fixing these ignition issues. I took it to an independent European car specialist after getting fed up with the unusual stalling. The mechanic did a thorough diagnostic check and found multiple problems, two bad ignition coils, a failing crankshaft sensor, and some corroded wiring in the engine bay. Total repair cost came to 780 Euro including parts and labor. The car ignition system works perfectly now, no more problems when I turn the key or unusual shutoffs. Engine starts right up every time and runs smooth. The dashboard lights all work normally too. Definitely worth getting it properly diagnosed and fixed by someone who knows these cars. Been about 4 months now with zero starting issues or electrical problems. Really glad I got it taken care of before getting stranded somewhere.