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FIXED (THANS SOUL!) Bad Valves or Grenaded Center Muffler?
991.2 GT3RS. Out for a drive today. Heard a weird fart/woof sound. Exhaust note got super deep and droney. Sounds like a riced-out Honda now. Valve button does nothing. Hard to see, but doesn't look like the valves are actually moving when button pressed, either. Vacuum lines appear connected but it's hard to tell. Running Soul side-bypass. Does this sound like a cracked/grenaded center muffler or something else?
If the center muffler gets a crack, wouldn't the valve button still change the sound slightly, as they are still re-routing exhaust through different parts of the muffler? Or there could be an internal crack rather than the external walls of the muffler...
Hard to be sure, but I also thought I smelled sulfur/rotten eggs once or twice.
EDIT: FIXED
It was a bad valve. Soul Performance took care of me.
Last edited by FourT6and2; 06-09-2022 at 12:52 PM.
I think it’s unlikely both valves are bad at the same time.
probably an exhaust leak or valves re not connected .
Yeah I was thinking the same thing... what are the odds both valves went bad at exact same time.
Doesn't sound like an exhaust leak (unless there's a hole in the center muffler that I can't see).
Valve vacuum lines appear connected. But hard to see without getting the car in the air. Do both valves' vacuum lines meet at one junction or are they connected to separate sources? Because maybe there's no vacuum for some reason, even with the rubber lines connected? As in... maybe the hard line(s) got disconnected or broken somewhere farther up the chain?
Simple guess is the vacuum line popped off on one side. They both eventually combine to one source so if only one popped it likely isn’t getting enough to move the valves. Easy fix if that’s what it is, you can see where they connect to the valves if you lay down next to the rear bumper on each side.
Simple guess is the vacuum line popped off on one side. They both eventually combine to one source so if only one popped it likely isn’t getting enough to move the valves. Easy fix if that’s what it is, you can see where they connect to the valves if you lay down next to the rear bumper on each side.
Ok perfect, thank you. That's what one of my suspicions was. That the vacuum lines are connected—so if one goes, they both go. I have Soul side bypasses and the lines connect at the top, rather than the bottom. So I can't see anything without the car in the air. I'll have to figure out a way to do that.
Last edited by FourT6and2; 05-31-2022 at 12:05 AM.
I checked the vacuum lines. At least all of the connections I can see from under the car. They are all connected. So if there is a vacuum problem, it's happening farther up the chain somewhere.
PSE button does nothing. Valves don't move when pressed. Under normal operation, they are supposed to actuate when car is idling.
There must be a vacuum pump that creates the suction to close the valves. That vacuum pump maybe went belly up? When disconnected the valves stay open and should be loud.
Have you checked the vacuum lines up top? You have to pull the 2 center fans but it's pretty easy. I had an issue with the lines up there that caused the valves not to work. I can take a picture later if that would help.
Have you checked the vacuum lines up top? You have to pull the 2 center fans but it's pretty easy. I had an issue with the lines up there that caused the valves not to work. I can take a picture later if that would help.
Yes. Each fan is held in by 3 or 4 grommets. Just pull up and you will see what I mean. They come out pretty easy. I will be home in a little bit and take a few pics for you.
Ok, so I forgot that the cover is one piece. Here are the photos. Check the white valves. Those are part of the system. Hope that helps! The cover has 8 contact points, 4 on each fan. The fans each have 3 contact points. 2 on top, one close. The 2 partially white valves are part of the system.
I have an RS, though. And the fan module and underlying components are slightly different. I'll have a look, but I'm gonna bring it to Porsche tomorrow as well.
Last edited by FourT6and2; 05-31-2022 at 07:41 PM.
You have a 3RS which means your center muffler is titanium. Center muffler damage happened to more than a few people running side bypass pipes on the titanium mufflers. If you replace it with a GT3 muffler I am confident you will fix the problem, unfortunately while picking up some weight.
05-30-2022 | 07:23 PM
FIXED (THANS SOUL!) Bad Valves or Grenaded Center Muffler?
