2root4u

I just went for a drive in my relative's stock Panamera 4S (v6 TT). Every shift under WOT it makes a horrible fart noise from the rear. He's really annoyed by it, and I find it hard to believe Porsche meant it to sound this way. After some searches, I haven't found anyone else complaining, so I'm wondering if his car has an issue. Being a previous turbo car owner and dealing with many blow off valves, the BOV is my first guess. Car is under boost, it shifts, and the blow off valves relieves the intake manifold pressure and it sound odd. My old car would sound like a goose honking when the BOV was shot. What's odd is that it sounds like the noise is from the rear, but I notice that the BOVs are piped to the sides of the engine bay, and I can't tell where they exhaust out.

Obviously he can take it in to the dealer to have it checked out, but has anyone seen/heard this before? Known issue? Ideas?

EMC2

I had the V8 P4S and never had any issues. On the contrary - sounded amazing.
I did test drive the newer 4S and the only thing that bugged me is that it sounded really subdued or unexciting in comparison. I would get it checked. Is it a version with PSE or not?

2root4u

No PSE. I will check in with him to see what the dealer says.

murdog

I have a 2014 Turbo (V8) that I believe does the same thing. I have about 5k miles on it and thought the sound was odd but it did not bother me. Though it made the car sound a little unique as I have had a lot of high performance cars but never one that made this type of noise on upshifts at hard throttle. Curious to see if this is normal or is there something wrong.