Exhaust Adaptive Valve

stevev · January 7, 2015

^welcome Jay. If you see some other threads, those owners that had their exhaust system replaced still had the squeak/chirp come back. Instead of wasting time at the dealer, I just clamped my valve open. But now I do get a slight drone in V4 mode.

Edited January 7, 2015 by stevev

Jaybridge88 · January 7, 2015

Well damn it! Haha. They said it was a "faulty valve" so I figured a new one would fix it. Thought I read someone thought it was redesigned. I'll go aftermarket...... eventually. Thanks for the info.

morrislee · January 12, 2015

Can someone help me understand? Is this valve normally opened when the truck is off? If that is the case, I should be able tp turn only one direction and clamp it down?

redwngr · January 12, 2015

The valve is to reduce the drone in V4 mode.

Here is one way to lock it open, 'for test purposes'.

Scroll down to the correct article: http://sandyblogs.com/techlink/?s=exhaust&search=Search

hotrodz37 · January 14, 2015

I clamped mine open due to the chirp. Have had it clamped open for about 9 months now and no issues, couldn't tell it was in v4 at all. I have completely stock exhaust, only change is the valve open. This morning on the drive to work, it kicked into v4 and I got the "helicopter noise" and it was pretty bad. Wondering if any of you are experiencing this? I am wondering why all of a sudden it started doing it.

MudMutt · January 15, 2015

I clamped mine open due to the chirp. Have had it clamped open for about 9 months now and no issues, couldn't tell it was in v4 at all. I have completely stock exhaust, only change is the valve open. This morning on the drive to work, it kicked into v4 and I got the "helicopter noise" and it was pretty bad. Wondering if any of you are experiencing this? I am wondering why all of a sudden it started doing it.

Could be your exhaust is starting to break in and flow a little better and now the v4 drone is a little more noticeable... I noticed mine drone is a little louder since I initially opened my flap also. I only have a little over 3K on the truck. I run the trans in M5 when I am not on the highway so the v4 won't engage.

smit303 · January 15, 2015

I had mine bolted open for a few weeks but had to revert to normal because I couldn't stand the drone in V4 mode. Very bad around 1200 rpms. The tiny improvement in sound quality when starting up just wasn't worth it.

f8l vnm · January 15, 2015

I did get the v4 drone when I turned mine open but it wasn't all that terrible I have to say. Kinda sounds like a helicopter is outside...lol hey man , I complain about a lot of other things but this one is ok , could be worse.

hotrodz37 · March 19, 2015

I wonder if there is any kind of lube/ high heat silicon or something to be able to get it to not squeak. Im going to do some research and see if I can find anything.

Jaybridge88 · March 20, 2015

The dealership changed my exaust system under warranty 3 weeks ago. While I was waiting for the new exhaust the dealership clamped my current exhaust open. Driving around like that for about 3 weeks.....the exhaust sounded lousy. Loud drone.....got a helicopter noise on decel. I've been driving around with the new exhaust for 3 weeks and it sounds a lot better than when it was clamped open. No squeaks yet. Time will tell. As far as I know it's just the same stock exhaust. They said the other exhaust had a faulty valve.

Silverado-Hareek · May 21, 2015

I seriously never had an issue with V4 and exhaust sound on my 2007. I loved the way the exhaust sounded on that truck actually. I want to change my exhaust to be exactly like that system so I guess I just need to remove the flapper valve and the resonator. I don't really care about the 3rd cat.

For the guys that clamped their valves open and then got a helicopter type sound, I'm wondering if that sound is from the air passing around the flapper in it's open state and if the flapper wasn't there, the air flow would be more smooth and eliminate that sound?

Edited May 21, 2015 by Silverado-Hareek

Jaybridge88 · May 21, 2015

Not sure if that flap clamped in the open position would cause the helicopter noise.

I had my whole exhaust replaced under waranty to fix the adaptive valve chirp. It was good for about 3k miles, but it is now chirping again when going from V4-V8.

So all I know is I'm done with this exhaust. Starting to research aftermarket exhausts. I recently drove across country from MA to CA pulling a 12 foot trailer. The trailer was packed. Couldn't fit another thing in it and I had my quad in the bed of the truck. Truck did great pulling through the Rockies. Love this truck but the exhaust has to go.

Can anyone recommend a muffler shop in the San Diego area?

Samason1 · May 28, 2015

I just got my 15' 2 weeks ago and the first thing I did was drive it from the dealer to my shop and do a full cat back flowmaster system and Volant CAI. Sounds way better than stock.

jdg24 · June 11, 2015

Just found out the thread I started would be helpful in this thread: http://www.gm-trucks.com/forums/topic/173454-strange-noise-coming-from-rear-end-passenger-side/

TheBigGrabowsky · November 13, 2015

I hope you guys are certain those nails aren't going to fall out. If that mod gets really popular and those nails aren't in there solid then we're going to have an epidemic of nails in tires.

Personally I'd just pay an exhaust shop $40 to cut out the flap. Even with it open it disrupts the airflow and creates unnecessary back pressure. This engine has to push through tiny exhaust manifolds, then 3 cats, a flapper and a muffler. Let that baby breath!