[johan]

As we know the exhaust valve have a tendency to rattle when it opens at 2000rpm.
On some other Porsche models the valve have it´s own mapping, open/closing depending on gear and rpm.
On the 718 it looks like there only is the 2000 - 50km/h limit.


My valve starts to rattle from time to time and its not the up and down motion that causes it, there is a play sideways.
On older Porsche you simply disconnect the power to the vacuum solenoid (where it is located on a 718 I have no idea) or disconnect the vacuum line, I might just do that........


Any thoughts or ideas?

 

[johan]

a quick test with some wire to keep the PSE open worked good.
One would also be able to put something to prevent the play to get rid of the rattle.

 

[JakiChan]

Ah...so the infamous R32 Flapper Mod is back in a new car!

 

[johan]

LoL

The thing is that if you compare the valve on the 718 against other Porsche models you will see that the valve aint in a good quality valve
There is nearly 1cm of play sideways but some DIY would prevent it from rattling .
It would not suprise me if that valve is gonna be a big issue later on for us.........

 

[Guaji]

I’d be curious if there is a fix for the rattle. I can make it rattle on demand at 2000 RPMs with sport exhaust active.

 

[johan]

I’d be curious if there is a fix for the rattle. I can make it rattle on demand at 2000 RPMs with sport exhaust active.

I am gonna try to take some pics on what causes the problem
Then mayby we can try to solve it.

 

[johan]

Its not only the play that´s making the noise it´s also the movement it sealf.
Some heat resistant grease might be the solution!

Fully in

And out

In another thread i mentioned that i did the 981 exhaust mod, here is a pic of the smal gap i have now, makes the sound even better

 

[johan]

Grease helped a little bit but not enough, a couple of weeks and it would be as normal i guess
If the axle is fully in/out and the valve engages you get the noise because it moves sideways.
So prevent it from moving in/out or prevent it to reach the end by 1-2mm would solve it
Or keep it fully open at all times.

 

[Guaji]

I came across this video since I was investigating aftermarket exhausts, which seem to delete the valve. Though the exhaust pictured in this demo is the base. The purist in me wants to keep it stock, however the aftermarket exhaust sounds appeals to my childish side.

 

[Viffermike]

Ah...so the infamous R32 Flapper Mod is back in a new car!

Hah. It's not just an R32 thang, or a VW AG thang. BMWs with the 2.0 N20/26 four and the N55 inline-six also have a 'flapper' that can be permanently opened by disconnecting a wire while the valve is open. On BMW's, the flapper completely closes off one side of the exhaust after the muffler, so it's a primarily a quieting mod.

Good to know that the wire-pull trick works on our cars, @johan. Good work! One question: Did you have to pull it while the valve was open (i.e., car running & mode on)?

 

[JakiChan]

Well, R32s were doing it back in 2004.

 

[johan]

Good to know that the wire-pull trick works on our cars, @johan. Good work! One question: Did you have to pull it while the valve was open (i.e., car running & mode on)?

The valve is stronger then one might think (spring loaded) so you need a couple of turns of wire.
I also tried to cut a small bit of vacuum tube and press it in where the gap is then i took of the wire and i only hear a CLONK when the valve opens
If you hover around 2000rp you will still hear the valve open/close like crazy but it does not rattle its only clonking.


With the Engine Of the valve i open and with the spring pressing it down so to do the wire thing is a walk in the park.
There is also the option to disconnect the vacuum and plug the holes on the valve/tube but its a pain to reach.


On certain models of Porsche you dont want the valve open at all time cause it causes drone at certain rpm:s but no such issue on the 718

 

[R Doug]

I’d be curious if there is a fix for the rattle. I can make it rattle on demand at 2000 RPMs with sport exhaust active.

@Guaji, does it sound like this?

 

[Guaji]

@Guaji, does it sound like this?

Yes, that’s the noise. I showed that video to the service tech before we went for a ride. I think it’s “normal” unfortunately and as mentioned before it happens at 2000 rpms and sport exhaust engaged.

 

[R Doug]

Yes, that’s the noise. I showed that video to the service tech before we went for a ride. I think it’s “normal” unfortunately and as mentioned before it happens at 2000 rpms and sport exhaust engaged.

Thanks for the reply. It has been driving me crazy since I've first heard it a year ago. That's my video which I did to show my service folks I'm not crazy. Of course, I can recreate it any time at 2K RMP with PSE engaged, just as you said.

 

[Guaji]

Thanks for the reply. It has been driving me crazy since I've first heard it a year ago. That's my video which I did to show my service folks I'm not crazy. Of course, I can recreate it any time at 2K RMP with PSE engaged, just as you said.

Great video. Thanks for that. Sometimes the noise makes me consider an after market exhaust, but it’s nice to have a quiet mode option. I like the sound of the Fabspeed but it deletes the valve.

 

[R Doug]

Help end my confusion on this. Is the value which rattles the actual value that's activated when PSE is engaged or is it some over valve? With PSE off (assuming the PSE valve is closed), I cannot replicate the rattle. It's only with PSE engaged am I able to create the rattle at 2K rpm.

 

[Guaji]

Help end my confusion on this. Is the value which rattles the actual value that's activated when PSE is engaged or is it some over valve? With PSE off (assuming the PSE valve is closed), I cannot replicate the rattle. It's only with PSE engaged am I able to create the rattle at 2K rpm.

That’s a good question. I have no idea how it functions. At first I thought some valve always remained open....but maybe it just actuates at 2000 rpms. @johan may know........

 

[johan]

That’s a good question. I have no idea how it functions. At first I thought some valve always remained open....but maybe it just actuates at 2000 rpms. @johan may know........

From what i understand, the valve is open when the car is of, turn on the ignition and it closes after a sec or two.
Turn on the PSE and drive but keep the revs under 2000rpm and the valve will stay closed, once over 50 km/h (31miles) it opens regardless of rpm.
In sport mode the (pdk) car changes gear higher up in the rpm range so it never will fall under 2000rpm most of the time.
So 2000rpm is the braking point and over 50km/h it also opens


Additional features.......
But there is more to it regarding the exhaust/note, but is nothing to do with the PSE.
I have been searching like crazy to find out why the note changes in sport mode.
A car without PSE or SC still sounds more in sport mode.
Sure the cracks and farts comes from some extra fuel igniting but the tone how is that produced?
The car also changes note in sport if its cold or varm. (easily heard on a pdk car)


Take a cold car and turn the ignition halfway and turn on the sport mode.
Start the car and listen to how it sounds while idling.
Press and hold the brake and put it in reverse or drive and sound lvl increases.
Do the same on a varm car and the sound lvl stays the same.

 

[MikePhDPE]

was there ever any resolution on this? Mine also makes this rattle and it's driving me crazy. is there an adjustment that can be made? or putting vacuum tube on the rod to cushion it?