PSE valves not opened fully when at 90C+
#16
Looked into it, sourcing some ramps so I can use this as a temporary fix until I can get to the root of the issue. However I do live in an apt next to some condos so I try to be quiet aka shut off exhaust when I'm getting home to keep eveyrone from hating me.
Still confused by what is causing them to get stuck like half-open and sound super 'baffled.' I'm thinking some high-temp grease on the valves and ball-joints, then checking all the vacuum lines is in order.
Has to be related to heat as when I start the car up after sitting for 24 hours or so I have no issues, but running it for 20 mins and I can recreate the issue now.
Still confused by what is causing them to get stuck like half-open and sound super 'baffled.' I'm thinking some high-temp grease on the valves and ball-joints, then checking all the vacuum lines is in order.
Has to be related to heat as when I start the car up after sitting for 24 hours or so I have no issues, but running it for 20 mins and I can recreate the issue now.
#17
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Thread Starter
you don’t need ramps, I’ve done it in mine which has lowered suspension and didnt need one. PSE won’t be loud If you drive slowly. I would do it — you get a nicer sounding exhaust especially at the lower part of the range when flooring the throttle. And you’d fix your sticky valves issue
That's fair, I won't mind it at all, just want to get the PSE feature itself fixed to work like OEM at some point incase I sell it later on. May just get it looked at when I do my 30k mi service in a few months.
Thanks for the push. I'll do it this weekend!
#18
I have the Techart Springs on and was unable to get my head under the passenger-rear last night. I also have a 7.5 hat size so maybe my noggin is too large? I couldn't see the valve easily at least.
That's fair, I won't mind it at all, just want to get the PSE feature itself fixed to work like OEM at some point incase I sell it later on. May just get it looked at when I do my 30k mi service in a few months.
Thanks for the push. I'll do it this weekend!
That's fair, I won't mind it at all, just want to get the PSE feature itself fixed to work like OEM at some point incase I sell it later on. May just get it looked at when I do my 30k mi service in a few months.
Thanks for the push. I'll do it this weekend!
#19
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Thread Starter
Already got vacuum caps from the 'Zone last night and have a bucket o' bolts for the hoses. No chances on any open anything.
That picture you posted earlier, is that of the valves on the exhaust closer to the wheels? Or is it one of the 2 in the dead center, right next to each other. behind the middle valence on the rear bumper?
#20
Already got vacuum caps from the 'Zone last night and have a bucket o' bolts for the hoses. No chances on any open anything.
That picture you posted earlier, is that of the valves on the exhaust closer to the wheels? Or is it one of the 2 in the dead center, right next to each other. behind the middle valence on the rear bumper?
That picture you posted earlier, is that of the valves on the exhaust closer to the wheels? Or is it one of the 2 in the dead center, right next to each other. behind the middle valence on the rear bumper?
Last edited by JLCarrera; 09-16-2021 at 01:46 PM.
#21
Just wondering-I’m having problems with my PSE as well. Got my head under the rear bumper this morning and they look OK. With the engine off, I can push each shaft up and down with no problem. When I start the engine, both valve shafts go up (inserted) into the valves. If I pull down on one of them (not easy to do), the exhaust tone does change. After shutoff, the valve shafts stay up and slowly come back out as the vacuum dissipates. Problem really seems electrical. Whether or not the PSE switch is on or off, it doesn’t seem to
do anything. Is there a fuse that could be bad?
do anything. Is there a fuse that could be bad?
#22
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So I have posted about something that has been racking my brain but may have implications to what is happening. I seem to notice a difference in exhaust tonality between the Sport Chrono cars and the non-SC cars. Supposedly same engine, same Porsche Sport Exhaust model number, but sound different. Since the stop sale for Sport Chrono cars, maybe it was a tuning difference that changed the sound, but I had a theory that the Sport Chrono cars changed the angle of their PSE valves to create a sound difference between the cars. I imagine the car can adjust vacuum to adjust the position of the valves? Or is it an on/off valve?
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#23
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So I have posted about something that has been racking my brain but may have implications to what is happening. I seem to notice a difference in exhaust tonality between the Sport Chrono cars and the non-SC cars. Supposedly same engine, same Porsche Sport Exhaust model number, but sound different. Since the stop sale for Sport Chrono cars, maybe it was a tuning difference that changed the sound, but I had a theory that the Sport Chrono cars changed the angle of their PSE valves to create a sound difference between the cars. I imagine the car can adjust vacuum to adjust the position of the valves? Or is it an on/off valve?
In short, they're on/off valves.
Sport Chrono cars have a slightly faster listed 0-60, but I always thought that was due to launch control.
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RGS (09-27-2021)
#24
Rennlist Member
Thread Starter
i found that pic online, don’t know where exactly it’s coming from. But if you have a 991.1 with PSE, then I believe you have two valves in the center of the center muffler. You only need to remove the hose from the master valve, as the other valve is a slave from the master. You’ll see what I mean when you get you head under the car.
Got some WD40 High Temp Grease coming this week and will grease up the valve arms when I am able to and reconnect to see if that will do it.
However having the valves wide open 100% of the time is nice.
#25
Rennlist Member
Thread Starter
Just wondering-I’m having problems with my PSE as well. Got my head under the rear bumper this morning and they look OK. With the engine off, I can push each shaft up and down with no problem. When I start the engine, both valve shafts go up (inserted) into the valves. If I pull down on one of them (not easy to do), the exhaust tone does change. After shutoff, the valve shafts stay up and slowly come back out as the vacuum dissipates. Problem really seems electrical. Whether or not the PSE switch is on or off, it doesn’t seem to
do anything. Is there a fuse that could be bad?
do anything. Is there a fuse that could be bad?
I have seen a lot of people have had the issue you have with a bad solenoid that turns the vacuum line On/Off on the top of the motor. Though most seem to come from Caymans with PSE from around teh same era, knowing Porsche it's the exact same part so that might be worth a swap if you can isolate to electrical as I think they run $125-ish. Good luck!
#26
Rennlist Member
Thread Starter
Without an encoder of some sort to give feedback on the valve position, it's a wildly inaccurate guessing game to adjust vacuum to actuate the valve to a given angle.
In short, they're on/off valves.
Sport Chrono cars have a slightly faster listed 0-60, but I always thought that was due to launch control.
In short, they're on/off valves.
Sport Chrono cars have a slightly faster listed 0-60, but I always thought that was due to launch control.
#27
My issue is that the left vavle (from the back) wouldn't come back down all the way. Seemed like it was physically stuck nothing to do with the vacuum.
I have seen a lot of people have had the issue you have with a bad solenoid that turns the vacuum line On/Off on the top of the motor. Though most seem to come from Caymans with PSE from around the same era, knowing Porsche it's the exact same part so that might be worth a swap if you can isolate to electrical as I think they run $125-ish. Good luck!
I have seen a lot of people have had the issue you have with a bad solenoid that turns the vacuum line On/Off on the top of the motor. Though most seem to come from Caymans with PSE from around the same era, knowing Porsche it's the exact same part so that might be worth a swap if you can isolate to electrical as I think they run $125-ish. Good luck!
thus I am wondering if mine is also stock. Not sure if its stuck closed or open.