Cayman's Black Smoke & Power Loss: Ignition Issue Alert

Hi there! I had a similar issue with my 2018 Porsche 718 Boxster (basically the Cayman's sibling). I have some experience working on cars, but this was definitely a workshop job. Had almost identical symptoms, rough running, jerking, and that frustrating power loss. Turned out to be a damaged cable connection to one of the ignition coils. My trusted mechanic found it pretty quickly and replaced the wiring harness and connectors. Cost me about 365€ to fix, but the car's been running perfectly since then. Could you share your CEL code and maybe tell me if the issues get worse when it rains? This might help confirm if we're dealing with the same problem. Also, have you noticed any specific cylinders misfiring? Hope this helps! Let me know if you need more details.

Thanks for sharing your experience! My symptoms do match what you described. My last service was just 2 months ago at 41513 KM, and everything was fine until last week. Haven't noticed any specific connection to rain, but I'll definitely keep an eye on that. Unfortunately, I haven't been able to pull the CEL code yet, was planning to do that tomorrow. I'm really hoping it's just the ignition coil issue like yours, as that seems relatively straightforward to fix. The jerking and power loss are seriously concerning though. Did your car also have that strong black smoke during acceleration? I'm wondering if I should limp it to the workshop or just get it towed to avoid any potential damage.

Hey again! Yeah, I can totally relate to your concern about the black smoke, my 718 Boxster had that exact same issue. It was pretty scary seeing that stuff coming out of the exhaust! In my case, the black smoke was definitely worse during hard acceleration, and yes, it was one of the symptoms along with the jerking and power loss. Looking back, I probably should've had it towed rather than driving it to the shop, I was pretty lucky nothing worse happened. When electrical connections to the ignition coils are compromised, you can get incomplete combustion, which explains the black smoke and poor performance. Given how similar your symptoms are to what I experienced (especially that nasty black smoke and jerking), I'd strongly recommend getting it towed. I know it's extra hassle and cost, but these Porsches are too precious to risk additional engine damage. Mine ended up being a relatively simple fix with the wiring harness, but driving with these symptoms could potentially cause more expensive problems. Quick tip from my experience, when you get the CEL code read, if it shows multiple cylinder misfires rather than just one, it could point to a wiring harness issue like mine rather than just a single bad coil. Would be really interested to hear what codes you get. Keep us posted!

Thanks so much for the detailed advice! You've definitely convinced me to play it safe and get it towed. Better to spend a bit on towing than risk bigger engine problems. I'll call my local Porsche workshop first thing tomorrow morning and arrange everything. Really appreciate the tip about checking for multiple cylinder misfires too, that's super helpful. I'll make sure to get those codes checked and share them here once I know more. It's actually quite reassuring to hear that your similar issue turned out to be something relatively straightforward to fix. Will update the thread once I get some answers from the workshop. You've really helped put my mind at ease. Thanks again for sharing your experience!