[1fstcat17]

I assume the exhaust actuator valves are open when engine is off. Is this correct? I plan on performing a smoke test on my exhaust and was wondering if the valves would interfere...

 

[Mattm400]

This is correct. Open when engine off.

 

[snobrdrdan]

I plan on performing a smoke test on my exhaust

 

[Slidd]

Smoke test? You know even when they're closed they're partially open right? There's a big hole right in the middle of the flapper valve to allow exhaust to flow even when closed.

Sent from my SM-N960U using Tapatalk

 

[Octanewide]

Smoke test? You know even when they're closed they're partially open right? There's a big hole right in the middle of the flapper valve to allow exhaust to flow even when closed.

Sent from my SM-N960U using Tapatalk

Yep...

Sent from my SM-G781V using Tapatalk

 

[1fstcat17]

To find a leak.

 

[1fstcat17]

Smoke test? You know even when they're closed they're partially open right? There's a big hole right in the middle of the flapper valve to allow exhaust to flow even when closed.

Sent from my SM-N960U using Tapatalk
[/Q

Smoke test? You know even when they're closed they're partially open right? There's a big hole right in the middle of the flapper valve to allow exhaust to flow even when closed.

Sent from my SM-N960U using Tapatalk

Smoke test? You know even when they're closed they're partially open right? There's a big hole right in the middle of the flapper valve to allow exhaust to flow even when closed.

Sent from my SM-N960U using Tapatalk

I am doing a smoke test to check for exhaust leaks. It's much easier than trying to feel for one with your hands, especially when it may be near the manifolds...

 

[Frosty]

I am doing a smoke test to check for exhaust leaks. It's much easier than trying to feel for one with your hands, especially when it may be near the manifolds...

Also much easier to find those pesky leaks that are only present when cold, like a leak at the connection between manifold and head. I bought a smoke machine about 2 years ago and they come in VERY handy in diagnosing things. Exhaust, intake/vacuum, EVAP, etc.

 

[Radride]

There will be a exhaust leak near the front. Every hellcat has it. I see black spots on the garage floor all the time from the water vapour and soot mixing.

R.K.

 

[Frosty]

There will be a exhaust leak near the front. Every hellcat has it. I see black spots on the garage floor all the time from the water vapour and soot mixing.

R.K.

At the slip joint, right? I've got a leak that I can hear (drives me nuts) during cold start and goes away after I hit running temp. I assumed it was that slip joint. I planned on doing what the OP is planning next time I get it on the lift.

I had thought of sliding the exhaust out of that joint, applying some Permatex Ultra copper RTV on it and putting the exhaust back together. Maybe overkill but that was what I was thinking of doing.

Permatex® Ultra Copper RTV 3.5oz – Permatex

www.permatex.com

 

[baabootoo]

There will be a exhaust leak near the front. Every hellcat has it. I see black spots on the garage floor all the time from the water vapour and soot mixing.

R.K.

From the valve itself, right? Don't they just blow exhaust directly out through the valve to the inside making the noise?

Just so we're on the same page, is this open (quiet) or closed (loud)?

 

[Radride]

From the valve itself, right? Don't they just blow exhaust directly out through the valve to the inside making the noise?

View attachment 592769 Just so we're on the same page, is this open (quiet) or closed (loud)?

Not from the valve. The valves are near the back of the car. The slip joint is at the front of the car (the area I'm talking about in my post).

R.K.

 

[baabootoo]

Ahhhhhhhh, ok. My slip joints are ok.

 

[1fstcat17]

The reason I am doing a smoke test is that I am continuing to get exhaust smell and fumes inside the cabin. I have taken it to two dealerships and they can not duplicate the problem. I hear what sounds like an exhaust leak at the head-manifold connection. May also be at the manifold to cat connection. I want to find out exactly where it is.

 

[1fstcat17]

There will be a exhaust leak near the front. Every hellcat has it. I see black spots on the garage floor all the time from the water vapour and soot mixing.

R.K.

My 2017 Charger Hellcat had that issue, but I have not noticed it on the Challenger Redeye...

 

[Octanewide]

From the valve itself, right? Don't they just blow exhaust directly out through the valve to the inside making the noise?

View attachment 592769 Just so we're on the same page, is this open (quiet) or closed (loud)?

That's the loud open position. When that valve is closed exhaust goes through that smaller hole in the center.

Sent from my SM-G781V using Tapatalk

 

[Frosty]

The reason I am doing a smoke test is that I am continuing to get exhaust smell and fumes inside the cabin. I have taken it to two dealerships and they can not duplicate the problem. I hear what sounds like an exhaust leak at the head-manifold connection. May also be at the manifold to cat connection. I want to find out exactly where it is.

You probably have a stuck open interior exhaust vent. Those are behind the bumper and allow air to escape the car when things like doors are closed to help with air pressure. Necessary to if airbags go out. I had this problem on my Viper and one of mine was bad. Exhaust leak or not, if your windows are not down you should not smell it inside the car if things are working correctly with those vents.

Their was another poster that had this issue recently. Not sure if they figured it out but it sounded like it was really bad for them so I'm hopefully they figured it out. You could probably put the smoke machine behind the rear tires and see if any smoke makes it into the car. Just have to find some way to get smoke to where those vents are and thinking that would be the best way.

 

[1fstcat17]

You probably have a stuck open interior exhaust vent. Those are behind the bumper and allow air to escape the car when things like doors are closed to help with air pressure. Necessary to if airbags go out. I had this problem on my Viper and one of mine was bad. Exhaust leak or not, if your windows are down you should not smell it inside the car if things are working correctly with those vents.

Their was another poster that had this issue recently. Not sure if they figured it out but it sounded like it was really bad for them so I'm hopefully they figured it out. You could probably put the smoke machine behind the rear tires and see if any smoke makes it into the car. Just have to find some way to get smoke to where those vents are and thinking that would be the best way.

Thanks Frosty! I pulled the rear trunk panel and checked the flapper vents. They appeared to be closed. I will try the test with the smoke machine and see if any enters the trunk.

 

[baabootoo]

That's the loud open position. When that valve is closed exhaust goes through that smaller hole in the center.

Sent from my SM-G781V using Tapatalk

Doesn't that exhaust go through the resonator then making it quieter? I thought the "loud" position was opposite of this when it blocks the resonator and forces exhaust noise (wide open w/o going through resonator) through the side vents of the actuator valve? When I crawled under and looked at it, that's the only thing that made sense. Do I have it backwards? Thanks.

 

[Octanewide]

Doesn't that exhaust go through the resonator then making it quieter? I thought the "loud" position was opposite of this when it blocks the resonator and forces exhaust noise (wide open w/o going through resonator) through the side vents of the actuator valve? When I crawled under and looked at it, that's the only thing that made sense. Do I have it backwards? Thanks.

Doesn't matter what resonator or muffler you have because when this valve is closed it will slightly quiet the exhaust. In this picture the valve is wide open and you can see the valve actuator on the side of the exhaust pipe there.

Sent from my SM-G781V using Tapatalk