Jump to content

Exhaust Flapper Whistle

19Sierra
 Share

Recommended Posts

19Sierra Enthusiast

19Sierra

Posted
Posted

Does anybody else notice a whistling noise coming from they're exhaust? Since the warmer weather I've been driving with the windows down and started noticing it everytime I accelerate. Very noticeable when something is along side the truck. I have the 5.3L with single side exit exhaust. 

 

I wired the flapper before the muffler open and the whistle completely disappeared. Only difference I notice with the flapper open is that the whistle is no longer there. Just curious if there's a problem with the flapper on my truck or if they all do it. 

 

Thank you.

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

I noticed it on my truck and my parents truck. They are both 2016's but the flapper stuff is all the same.

 

I have an aftermarket exhaust now so that's all gone.

19Sierra Enthusiast

19Sierra

Posted
  • Author
Posted
On 5/18/2020 at 12:14 AM, CamGTP said:

I noticed it on my truck and my parents truck. They are both 2016's but the flapper stuff is all the same.

 

 

I have an aftermarket exhaust now so that's all gone.

Guess we are the only ones who noticed it. Lol after having it wired open for almost a week the only difference I can tell is that it doesnt whistle anymore. Doesnt seem to do anything else. 

19Sierra Enthusiast

19Sierra

Posted
  • Author
Posted
5 hours ago, jnissen said:

Was the flapper a one way valve for deep water? Sorry but new to GM trucks.

From my understanding and from watching this video it appears that its purpose is to quiet idle noise. I cant tell a difference in noise with it open or closed. If it has another function than I would be interested to know. 

 

 

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

They say it also helps drown out the AFM/DoD system because the valve gives it another thing to interrupt the exhaust pulses.

  • 7 months later...
JohnH4260 Enthusiast

JohnH4260

Posted
Posted
On 5/17/2020 at 2:52 PM, 19Sierra said:

Does anybody else notice a whistling noise coming from they're exhaust? Since the warmer weather I've been driving with the windows down and started noticing it everytime I accelerate. Very noticeable when something is along side the truck. I have the 5.3L with single side exit exhaust. 

 

I wired the flapper before the muffler open and the whistle completely disappeared. Only difference I notice with the flapper open is that the whistle is no longer there. Just curious if there's a problem with the flapper on my truck or if they all do it. 

 

Thank you.

How did you wire the valve open?

19Sierra Enthusiast

19Sierra

Posted
  • Author
Posted
32 minutes ago, JohnH4260 said:

How did you wire the valve open?

32 minutes ago, JohnH4260 said:

How did you wire the valve open?

 

20200517_131035.jpg

  • Thanks 1
19Sierra Enthusiast

19Sierra

Posted
  • Author
Posted
16 minutes ago, JohnH4260 said:

Thank you for the photo. What gauge wire did you use?

I think I used .045 or 1/16". I recommend using stainless so it doesn't rust. If you have a welding supply store near by just stop in and ask for a piece of .045 or 1/16 stainless filler metal.

  • Thanks 1
JohnH4260 Enthusiast

JohnH4260

Posted
Posted
On 1/11/2021 at 7:51 PM, 19Sierra said:

I think I used .045 or 1/16". I recommend using stainless so it doesn't rust. If you have a welding supply store near by just stop in and ask for a piece of .045 or 1/16 stainless filler metal.

Thank you.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • KARNUT
      Trading 7.3 (Godzilla) for G.M.C gas

      By KARNUT · Posted

      My nephews 7.3 got noisy right around 100K miles. While replacing the engine he drove his old 6.0 Chevy that had over 200K miles on it. It an old reliable backup. I haven’t been around the old shop lately. I’m curious to find out if there using the new GM heavy duty gas.
    • Atlas
      Wow I'm in a pickle. (Broke down truck) and a story.

      By Atlas · Posted

      I don't know if you or anyone enjoys it or not but, why not share it. It's GM "truck" related and we're in the right place to discuss that 😉 I'm also working on some creative writing skills, I'm not quitting my day job to pursue that, either!   As I said, I've hit a wall because I'm not making any progress, and the progress is the fun part for me.   The idler pulley and EGR valve came in. Against better judgement, I went out there last night and put both of them in. I was able to get a nut on the back of the bolt on the side with the broken flange. There's enough flange still there that I can get that side of the EGR to snug down. It's not perfect, it's not "right", but this is the fix I have for now. If I decide to keep the rig, I talked to a guy locally who will sell me a complete intake for $100. If it's my truck, a broken flange like that would bug me too much. Yes, I'm crazy. But I embrace it.   Pulley on, EGR installed, started the truck. Great...still have a pulley squeaking like mad. That was the first disappointment. I thought I had pinpointed the problem. Before I replaced it, I sprayed the back of that pulley with PTFE and it would shut up for about 30 seconds. Is the squeak actually the belt? I'm frustrated.   SO then I decided why not disappoint myself twice, so I took it for a spin and sure enough, the CEL set for P0401 insufficient EGR flow again.   I had some extra time, so when I arrived home, I decided to ask AI about my EGR code. We had an interesting conversation.   I asked how to tell if my MAP sensor is bad and if that could be setting an EGR code since a bad MAP may not be sensing the requisite drop in manifold pressure when the EGR activates. I gave it the MAP value at idle and it told me to blip the throttle hard and watch the MAP reading. It said no, the values appear normal and it's reactive to pressure changes, and then instructed me to test voltage at the harness. I don't think it's the MAP sensor. Interesting, though, I gave it MAP reading values in inHg, and it thought I was using PSI, so I had to correct it. AI is a very dangerous tool if you aren't treating it like the machine that it is.   Then it walked me through testing the EGR and harness. It took me down an interesting path. It was referencing a gray wire and a white wire so I told it I can't tell the difference on my harness because it's dirty and old and both could be white or gray, I'm not sure. So it gave me a more accurate description of the ABCDE pins on the connector and started referencing pins instead of colors. Helpful.   The EGR harness has 12v power, and it also has 5v reference power from the PCM. What I'm unclear on is there's a ground wire and I thought AI had said that one of my tests revealed the ground in the harness was likely bad and it instructed me to wire a test ground. I got distracted and navigated away from the AI conversation, and when I went back and asked for clarification it said I must have misunderstood. (how rude- next time I'm saving the conversation!)   But I think it was onto something. I recall NOT getting 12v when I tested the power wire to the ground wire, but I did when I tested the power wire, grounding the voltmeter to the engine block. AI said no, the ground wire is actually for the PCM, that's how it commands the EGR on by grounding it and so the circuit should be open with the key on (i.e. EGR off). But I think there's also a static/overall ground that should always be grounded, and if that's bad, then the EGR isn't activating when the PCM commands it on, and thus setting the code.   There's a bunch of other tests it suggested, back-probing with the EGR plugged in and engine running. I need to get some time to focus, and not just tinkering after a long day.  
    • kylant
      Trading 7.3 (Godzilla) for G.M.C gas

      By kylant · Posted

      the 7.3 lifter issue is real, not few and far between.  my 6.6 gas does not use oil.  the 7.3 with 4.30 gears pulled hills better and felt better off the line. the 6.6 gets the job done though. mpg sucks
    • kylant
      Remote Start Noise 2024 2500 HD Gas

      By kylant · Posted

      are you talking about the loud whooshing, grinding type noise? mine does it too
    • Donstar
      Slate Electric Truck

      By Donstar · Posted

      I am a huge fan of the Slate.  (SUV for her, base pickup for me.)  Unfortunately, there are no plans to sell in Canada but maybe this will change.  I think if/when Ford offered a high range. EV Maverick, it would be my first choice.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...