2014 Nissan Wingroad Diesel Experiencing Black Smoke, Engine Instability, and Possible Sensor Issues

Hey, you're spot on about suspecting the boost pressure control position sensor. Funny thing, I faced something quite similar in my 2011 Nissan Sentra. The symptoms were almost identical—rough idling, power loss, and that annoying whistle. This turned out to be a defective electrical bypass valve. Basically, this thing controls how much turbo boost your engine gets, so when it goes south, it messes with the engine's performance big time, as you've clearly noticed. In my case, my trusty mechanic ran a diagnostic scan which confirmed the problem, and then the valve was replaced. Mind you, it wasn't a humongous job but not a walk in the park either. The main thing was getting the exact replacement part, as apparently, these things are pretty model specific. After it was fixed, my car was back to its old peppy self, no more black smoke or weird noises! So, fingers crossed it's the same for you. Yeah, nobody likes to see the mechanic, but sometimes there's no avoiding it. Take it in, armed with this info and the rest should be smooth sailing. Keep us posted!

(Translated from German)

Hey, cheers for the info! It's comforting to find someone who's dealt with the same thing. Glad to hear your Nissan Sentra is running like a charm now. Just curious, do you remember how much it set you back to replace the electrical bypass valve? Also, has anything else cropped up since the repair or has it been all smooth cruising? It'd be good to know, since it seems our cars might be pulling the same stunts. Cheers again!

(Translated from German)

Hey, no problem, always happy to help a fellow car enthusiast! Regarding the cost, for the electrical bypass valve repair job, it set me back about 250€. And trust me, it was worth every single cent since there's no more that grumbling noise under the hood or the lurching when I hit the gas. As for your other question, I haven't had any other issues crop up after getting that fixed. It's been smooth cruising ever since, touch wood. Actually funny you should mention the boost pressure control position sensor issue, because that was indeed an issue on my Sentra too, but got it sorted during my visit to the mechanic. So, it seems we are indeed sailing in the same boat. Hopefully, knowing this puts a bit more wind in your sails! Let us know how it turns out, yeah? Cheers!

(Translated from German)

Wow, thanks heaps for the detailed reply! I'll keep your experience with the Sentra in my mind when I drop my wingroad off at the mechanic's. It's a relief to know what to expect cost-wise, and to hear that the fix has been long-lasting for you. Here's hoping my car will soon be back to normal as well. I'll definitely keep you posted. Cheers!

(Translated from German)