Black Smoke & Power Loss: Panamera Diesel Woes

Hey! I had very similar symptoms on my 2018 Cayenne Diesel last year at 132k km. The black smoke and power loss got me worried too. Turned out it was indeed the electrical bypass valve that was stuck partially open, causing irregular boost pressure. Had it fixed at the official Porsche service center, definitely not a DIY job as it required specific diagnostic tools and programming. The repair involved replacing the bypass valve assembly and recalibrating the engine management system. It was a fairly serious issue that needed immediate attention to prevent further damage to the turbo system. The whistling sound you mentioned was a dead giveaway, exactly what I experienced when my valve was failing. If you're having trust issues with your current mechanic, I'd strongly recommend going to an authorized Porsche dealer for this one. They have the right diagnostic equipment and expertise, especially for these newer models with complex engine management systems. Based on my experience, don't wait too long to get it checked. The symptoms you're describing are nearly identical to what I dealt with, and these issues tend to get worse quickly.

Thanks! Yeah, that sounds exactly like what I'm dealing with. The valve issue makes total sense given the symptoms. If you don't mind me asking, what did you end up paying for the whole fix? And has everything been running smooth since, or did you run into any other issues? Want to make sure I'm prepared for what I might be facing at the dealer.

Hey again! Glad I could help! Yeah, I took my Cayenne to the dealer last month and you'll be relieved to know they sorted it out completely. The Boost pressure control position sensor was definitely the culprit, just like we thought. Cost me 250€ to fix the faulty electrical bypass valve, which honestly wasn't as bad as I was expecting for a Porsche repair! The car's been running like a dream since then, no more black smoke, weird noises, or power issues. It's actually amazing how much of a difference fixing that one component made. The engine's super smooth now, and I'm getting proper acceleration again without any of that jerking nonsense. Trust me, getting it done at the dealer was worth every penny. These newer Porsches are pretty complex beasts, and you really want someone who knows what they're doing with all the electronic systems. One tip though, might be worth having them do a full diagnostic while it's in there, just to make sure there's nothing else brewing. Better safe than sorry with these cars, right?

Oh you've been a massive help! I actually just got back from the Porsche dealer and you were spot on. Took your advice and went straight to them instead of my usual guy. They found the exact same issue, faulty bypass valve causing all that drama. Funny enough, my repair came in at around 280€, just a bit more than what you paid. Money well spent though! They had it done in a day, and the difference is like night and day. No more black smoke show behind me, that annoying whistle's gone, and she's running smooth as butter now. Did take your tip about the full diagnostic too, turned out everything else was actually in pretty good shape, which was a relief. The service guys were really thorough and explained everything clearly, none of that dodgy mechanic speak I used to get. Thanks again for sharing your experience, saved me a lot of headache and probably some cash too by going straight to the right place. Definitely learned my lesson about trying to cut corners with these machines!