Borntostun

Hi everyone. I recently picked up a '12 Grand Sport. Love the car. Love the sound (related the post).

But . . .

Recognizing it's always pretty loud, I checked in on the dual performance exhaust option and mine appears to not be working. Though movable with by hand, the baffles remain in the open position no matter what. At idle . . . at all speeds . . .

Checked the fuse panel . . . it's there. Even replaced the fuse with another just in case . . . and still no effect. Checked for any Mild to Wild mod that perhaps the previous owner did . . . nothing there.

So . . . I thought to check in here . . . I am thinking solenoid? Has anyone else had this issue and found a fix? Just not too confident that my GMMEP will cover it at the dealer.

Thanks everyone. Appreciate it.

Blindfingers

I'm thinking two possibilities, one you covered.
Since there is no evidence of a Mild-to-Wild switch then you should check for a vacuum leak. Engine vacuum is what closes the valves so your solenoid may be the culprit.

Good luck.

ringo11

had the same issue on my 13 GS, solenoid in the back was bad, warranty covered it.

montman

Make sure that the vacuum hoses are connected to the diaphragms that move the valves.

montman

I forgot to mention it, but after you get it working, there's a way to hold the valves open about a quarter of an inch. This will allow you to enjoy a nice subtle growl without it being too loud. www.nakidparts.com sells some collars that keep valves open and they're adjustable. Or you can put some cable clamps on the shaft to keep them from closing all the way. Sounds great.

twinarrow99

My money is on a bad solenoid. Happened to me a while back.

Evander Holyfield

Plus one. Had it happen on my old '08- bad solenoid. I had the reverse problem- mine were stuck in the closed position.

Replaced under GMPP warranty at the time.

BadToo

Bad solenoid here too. The one behind the RR tail light. There are some "how to change it" write-ups on this forum.

Borntostun

Thanks all. Turned out to be a punctured hose . . . pretty quick fix.

Renarello

Same problem.
Thanks for the info!