Hey there! I've got some experience with cars (moderate level), and I actually faced almost the exact same issue with my 2009 Porsche Panamera Diesel last year. The symptoms were identical to what you're describing. My workshop diagnosed it as a faulty camshaft sensor, and they were spot on. The repair set me back about 695€, but it fixed all those annoying issues, the rough running, unusual shutdowns, and cold start problems disappeared completely. Before I share more details about my repair experience, could you tell me: How many miles/km are on your Cayenne? Have you had any other engine-related repairs recently? Are you getting any specific error codes?

Thanks for asking! My Cayenne has 52182 KM on the clock, and my last service was about 3 months ago where they just did routine maintenance. I'm getting an error code, but I'll need to check my paperwork at home to confirm which one it was. Your experience with the camshaft sensor sounds really similar to what I'm dealing with. That's actually a relief to hear it was a fixable issue in your case. Did you notice any warning signs before it got really bad? I'm planning to take it to my mechanic next week but wanted to gather some info first.

Hey again! Yeah, looking back at my Panamera's situation, there were definitely some warning signs before it got really bad. At first, I noticed the engine would occasionally hesitate or stutter, especially during cold mornings, but I brushed it off (big mistake!). The check engine light started flickering intermittently about a week before things went south. In my case, the car had about 63,000 KM when the sensor went bad, so pretty close to your mileage. The really scary part was when it first shut off while I was driving on the highway, that's when I knew I couldn't ignore it anymore. Just to be clear though, don't wait like I did! I was lucky nothing serious happened. From what you're describing and based on my experience, it really does sound like the same camshaft sensor issue. The symptoms match up perfectly, especially the cold start problems and unusual shutoffs. Quick tip: when you go to your mechanic next week, ask them to check both the sensor and the wiring harness. In my repair, they found that some of the wiring had gotten a bit corroded too. Getting that sorted at the same time saved me from potential future headaches. Let me know how it goes with your mechanic! Always curious to hear if others have the same fix work out for them.

Thank you so much for all this detailed info! It's super helpful to hear about your experience, especially the part about checking the wiring harness too, I'll definitely mention that to my mechanic. You've actually made me feel a lot better about the whole situation, knowing it's likely fixable and not some massive engine problem. I just checked my paperwork, and the error code is P0340, which I'm guessing is probably the same one you had. I'm definitely not going to wait around on this one after hearing about your highway experience, yikes! I've already called my mechanic and moved my appointment up to this Friday instead of next week. Better safe than sorry, right? Really appreciate you taking the time to share your experience. I'll update the thread once I get it fixed to help others who might run into the same issue!