Well, it's been years since I've been active on Rennlist, and I can no longer update my signature, but I'm back in the Porsche game! I picked up a really clean 2015 970 GTS a couple weeks ago. Independent PPI went really well, but looks like we missed the PSE. The light on the console does turn on and off, and there are no codes, but there's no active change in the sound.

I got behind the car and saw the PSE valves were closed, even at cold start. Changing Sport / Sport Plus / turning the PSE on and off didn't do anything to open them up, and I can't hear a solenoid actuate. Vacuum lines looked fine (and from what I gather, if it was a vacuum issue they'd be stuck open). So I tried manually operating them, and couldn't. With a flat head screwdriver I was finally able to leverage both of them open - I'm guessing the PSE hasn't been used in years because the corrosion was pretty severe, but now I can freely move the plunger for each with my hand, but as soon as I let go they slap back shut.

So, a couple questions:

1. Since the failure is them shut rather than open, I'm guessing the solenoid under the trunk carpet might be shot - is that a good place to start? If so, are there any good guides on diagnosing and replacing it?
2. Is there a good way to manually temporarily tie them open without causing issues?

TIA!

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Edit: So I just went out and manually opened them a few more times, and then pulled the vacuum tubes and then was able to pry them all the way open and stay there. I reconnected the vacuum tubes and they stayed open, but then when I pushed the PSE button they closed. So the corrosion then had been broken up enough to allow the system to close them, but it couldn't open them until I removed the tubes again and worked the plungers repeatedly. All works now!

 

I had similar issue, the car I bought has spend some time at the dealership due to the pandemic. Do not force them real hard. It is better to soak the joints, leave them overnight rinse and repeat. WD-40 or a good spray for bolts should do it.