996 PSE, no goose bumps, get it checked.
Discussion
I have now owned my 2003 996 Carrera 2 for about 3 months and done all the usual recommended upgrades and mods to future proof it as best as possible. Whilst replacing the engine mounts I took the opportunity to examine the state of the vacuum units and linkages that operate the valves in the PSE unit as the increase in exhaust volume/sound from stealth to sports was disappointingly low and was nowhere near the DB levels shown on the numerous YouTube vids.
Now whilst I am way to old to be a boy racer wanting an overly loud exhaust, I do like my cars to work properly and if the PSE was supposed to be as good as forums say, something needed to be done. On inspection one valve was totally inoperative in the closed position (seized ball joint in the linkage) and the second valve only opening half way due to partial valve spindle seizure. Both vacuum units were working fine so half an hour un-seizing and properly lubricating the system resulted in the valves both working as they should. Whilst these units can seize in the open or shut positions they can also fail at any position in between giving you only "partial" PSE sound.
The only issue that remained was the annoying automatic overide of the PSE between 30-45mph (Euro drive by sound regs apparently). This has been discussed many times on PH with a number of solutions put forward including the disconnection of the PSE vacuum pump in the engine bay, disconnection of the speed indication feedwire to the PSE relay or removing "snipping" the diode in the PSE relay.
Not wanting to perform surgery on the wiring loom and also wanting to keep the stealth button on the dash working I opted for the other suggested solution which was to carefully bend terminal 1 on the PSE relay 90 degrees so that terminal (speed signal) no longer connects when the relay is replaced. 30 second job that works as described, gives PSE at all speeds and is reversible if required.
In summary..... with PSE switched on, if your car sounds anything less than awesome get yourself under the back end (bumper and heat shields off, 15 mins with hand tools) and check the valves/linkages have not seized (then cancel the automatic override!).
Now whilst I am way to old to be a boy racer wanting an overly loud exhaust, I do like my cars to work properly and if the PSE was supposed to be as good as forums say, something needed to be done. On inspection one valve was totally inoperative in the closed position (seized ball joint in the linkage) and the second valve only opening half way due to partial valve spindle seizure. Both vacuum units were working fine so half an hour un-seizing and properly lubricating the system resulted in the valves both working as they should. Whilst these units can seize in the open or shut positions they can also fail at any position in between giving you only "partial" PSE sound.
The only issue that remained was the annoying automatic overide of the PSE between 30-45mph (Euro drive by sound regs apparently). This has been discussed many times on PH with a number of solutions put forward including the disconnection of the PSE vacuum pump in the engine bay, disconnection of the speed indication feedwire to the PSE relay or removing "snipping" the diode in the PSE relay.
Not wanting to perform surgery on the wiring loom and also wanting to keep the stealth button on the dash working I opted for the other suggested solution which was to carefully bend terminal 1 on the PSE relay 90 degrees so that terminal (speed signal) no longer connects when the relay is replaced. 30 second job that works as described, gives PSE at all speeds and is reversible if required.
In summary..... with PSE switched on, if your car sounds anything less than awesome get yourself under the back end (bumper and heat shields off, 15 mins with hand tools) and check the valves/linkages have not seized (then cancel the automatic override!).
Noble P4 said:
carefully bend terminal 1 on the PSE relay 90 degrees so that terminal (speed signal) no longer connects when the relay is replaced. 30 second job that works as described, gives PSE at all speeds and is reversible if required.
did this some time ago on mine, sounds great
Gassing Station | 911/Carrera GT | Top of Page | What's New | My Stuff