FX Diesel: Black Smoke & Power Loss Boost Issues?

Hey there! I had a similar issue with my 2012 Infiniti QX70 diesel (some experience with cars, been working on them as a hobby). That whistling and power loss sounds exactly like what I dealt with last year turned out to be a faulty waste gate valve. My symptoms were pretty much identical: black smoke, rough idle, and that annoying whistle during acceleration. It set me back about 860€ at my regular workshop, but they did a great job fixing it. Could you share your mileage and if you've noticed any other symptoms? Also, have you checked if there are any boost-related error codes? This info would help confirm if we're dealing with the same issue.

Thanks for the input! Mine's at 20913 KM and just had its service last month. To add to what I'm experiencing I've noticed the whistle gets louder when going uphill or during hard acceleration. Haven't pulled the error codes yet, but planning to get that checked tomorrow. Did your waste gate issue develop suddenly, or was it gradual? Really hoping it's not going to cost me as much as yours did!

Hey again! Yeah, I remember my waste gate problem pretty well. The way you described that whistle getting louder on hills that's exactly how mine started! In my case, it was pretty gradual at first started with just a faint whistle that I barely noticed, but over about 2-3 weeks, it got more noticeable, especially when pushing the car uphill. The black smoke and power loss came later. Given that your mileage is only at 20913 KM, you might be luckier than I was mine happened at around 95000 KM, which is probably why it cost me more. The components were more worn out. Honestly, you might be looking at a less expensive fix if it's caught early. Definitely get those error codes checked mine threw a P0299 code (that's for underboost condition). Would be interesting to know if you get the same one. And hey, since you just had service last month, maybe check if it's still under any warranty? Could save you some cash there! Let me know what the code reading shows curious to see if we're really dealing with the same gremlin here!

Thanks so much for the detailed response! That's really helpful to know about the gradual progression mine actually started pretty suddenly, like within the last week. Just checked my service paperwork and I might be in luck looks like I've still got about 2 months left on the extended warranty! I'll definitely update you tomorrow after getting those error codes read. Really appreciate you sharing your experience it's given me a much better idea of what I might be dealing with. Fingers crossed it's covered under warranty and won't hit my wallet as hard as yours did! Thanks again for all the help!