Poppy21

I need some help trouble shooting or my 2008 C6 dual mode exhaust system. Presently I can start my car and the valves close as normal. After running the car for about 10 minutes the valves fail to the open position. It seems to me that there may be and issue with an electrical controller (which I have no idea where it is located) or a vacuum hose leak that is located near the exhaust that heats up causing the leak to be greater that the vacuum. Either way I need a diagram showing how the system works so that I can fully troubleshoot the problem. Or maybe someone that has had this happen to them that can point me in the right direction. Any help is appreciated as I do not want to put it on the shop. Thanks

Corvette_Ed

Are you just sitting at an idle waiting for them to open, or are you WOT and they aren't opening?

Poppy21

When I leave the house they are operating perfect. After driving for 5 or 10 minutes that open up and stay open. This happens every time from a cold start. Once the car heats up they stay open.

Suds

The controller may be heating up, it draws current in the closed position.
I believe it's behind the right storage box in the car's trunk.

Poppy21

Thanks, I''l start there.

Suds

I read on a post its behind the passenger rear tail lights, not sure of the best way to get there.

unixcorn

Here are a couple of threads that explain where the controller is and how to remove it.

https://www.corvetteforum.com/forums...st-issues.html

https://www.corvetteforum.com/forums...tuck-open.html

LMB-Z

Its behind the passenger side tail lights. Difficult to get to but doable. Replaced mine, I think about $35.00.

Poppy21

Thanks everyone for the troubleshooting tips. I found the bad vacuum module behind the tail lights as instructed. Pulled, trouble shot and confirmed that the controller was bad. Got part on order. Will replace tomorrow. Thanks !!!

joint

I just got my dual mode exhaust working again. The problem is most probably the solenoid. Located behind the passenger side tail lights. Remove the two lenses with a torx bit. The solenoid is just inside and covered by a felt or plastic cover. Pull one side of the cover over to the side. I had to actually cut the right side and fold it over to the right side. It's just to keep some of the dust and debris off of the solenoid. Once the solenoid is in sight, remove the two vac lines carefully. I sprayed a little WD-40 on the lines then worked back and fourth until they came off. Remove the electrical connector. Now pull the solenoid toward the rear of the car to remove it from the bracket. No tools required for any of this. The new GM part number is 25794610. I actually ordered mine on Amazon. About $55 bucks. The old one was full of dust and obviously seized. If you start your car then turn it off, you will hear the air once you pull off the vacuum line that goes toward the engine. This should tell you that the vac lines are okay all the way to the engine and that the solenoid is the problem. Maybe spray a little WD-40 on the actuators too located on the two inner pipes.(butterfly valves). This should get you working. Mine did the same thing. It worked, then they failed open many times until finally stopped working completely. Good luck.

96GS#007

2016 called and wants its thread back

Zombie thread lives!

bjmsam

Thank you for contributing this relevant info to an existing thread rather than starting yet another one.

phileaglesfan

Good info though

buckmeister2

He said they are staying open, not closed