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Windymiller

PSE issues - 987.2S

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Becoming a little ‘teased’ by the car - just spent £2.5k on her for servicing and cosmetics refresh and first of all she throws up engine compartment fan warnings (see other post), and now the PSE seems to have failed to permanently on (not necessarily a bad state of affairs 😉😁). 
 

symptoms:

1) day 1 - raspy-rattle from exhaust after start up that went if PSE engaged

2) day 2 (after ~150 miles of spirited Ayrshire coast road blasting) - no apparent PSE ‘off’ functionality. 
3) day 3 (~400 miles / 6hrs of drive from Ayr to Bucks), PSE button has nil effect on exhaust note, seems to be always on. 
 

after trawling all the usual sites I’m thinking it’s one (or more) of:

1) PSE solenoid failed (this sits in the engine compartment) ~£20

https://m.buycarparts.co.uk/oen/99660512301?gadw=1&gclid=EAIaIQobChMI-cnO59e_6AIVwbHtCh0y3AcYEAAYASAAEgK3qvD_BwE

2) PSE vacuum pipe disconnected somewhere between solenoid and actuator)

3) PSE vacuum actuator (the thing that actually operates the exhaust valves - sat on rear mufflers) stuck / broken (a common issue). ~£95 for OE Porsche / ~£45 for Design 911 aftermarket. 
https://www.design911.co.uk/pages/productList.aspx?search=99711168001

 

unfortunately the car is in one location and I’m now in another for a week or more so unable to conduct any fault investigation.  


to change the vacuum actuators involves rear bumper removal. 
 

anyone experienced and resolved similar?

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Bit of an update on this:

 

Both valve actuators (the moving-thingy on each rear silencer just up behind the bumper) have full free range of movement by hand - they have a tendency to stick in one position or other.
 

The ‘push-rods’ from the actuators to the silencers are undamaged and appear connected - these can sometimes snap.

 

The vacuum pump is assumed to be working as it provides vacuum to other systems (eg brakes servo), and these work, so.... 🤷‍♂️
 

I replaced the Vacuum solenoid switch in the engine compartment with a brand new one from Porsche. During fitting I checked the vacuum draw to/from the 2 pipes connecting to the solenoid and they seem

fine (so assuming no holes/leaks in these pipes). 
 

so I’m at a bit of a loss now. The only other ‘component’ in the PSE system is one of the electronic control units through which the PSE operation signals pass (under passenger seat I think). 
 

ok, so it’s not the worst problem in the world to have that I can’t switch off my sports exhaust, but it bugs me that I have a switchable exhaust that isn’t working 🤨

 

any thoughts 🤔

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How annoying.

 

I'll take your insolvable exhaust problems in part-exchange for some random alarm issues if you fancy a change ?

 

**PM me if interested 🤣

  • Confused 1

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Check the vacuum lines between the PSE solenoid via the Y splitter to the actuators on the exhausts.

If there is a leak, the exhaust will remain loud and/or the actuators start rattling as there is no enough vacuum to shut them

  • Thanks 1

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38 minutes ago, @carnewal said:

Check the vacuum lines between the PSE solenoid via the Y splitter to the actuators on the exhausts.

If there is a leak, the exhaust will remain loud and/or the actuators start rattling as there is no enough vacuum to shut them

Thanks Gert, will do - I presume I’ll have to get under the car again to get to the Y-splitter 🤔

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Used a mates ramp to get the car up and using his hand-held vacuum pump and by process of elimination (disconnecting each tube / braided hose in turn and applying vacuum to see if it did / didn’t hold) I’ve confirmed it’s actually the LHS (passenger) exhaust valve actuator. 
 

on D911 an OE Porsche one is £105+VAT+P&P! 😱

 

or they do a design tek one for £38+VAT+P&P. 
 

clearly I’d rather buy the design tek one on price alone. Anyone used these? Are they as good quality as OE? Anyone used anything else instead - e.g., Helical?

 

also anyone changed one - is it a bumper off job? It looks doable with bumper on with small hands so long as the bolts that hold the actuator on an inverted bracket aren’t seized. 🤔

Edited by Windymiller
Price correction

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I have the EXACT same problem on my 987.2 S funny enough . I was searching through forums too see if anyone had any clue how to solve it since my dealer here in Sweden just told me to replace the whole muffler (£1500 + labor). 

 

For me the rattling comes from the actuator on the right side, but it seems to be the left that isn't working properly as it only closes "half way". If I manually close the left actuator, the rattling from the right side stops...🤷‍♂️

 

Sounds like this is what happened to you as well?

 

Now my concern is whether replacing the left actuator will solve the problem or if there's something faulty with the vacuum pump causing it not to open. Good idea to use a manual pump, although i'm not sure how much vacuum the cars own pump is supposed to deliver..

 

Let me know if it works out for you! 

 

BR
Johan 

 

 

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I think if one of the actuators (Vacuum unit) develops a leak (ie its internal diaphragm splits / perforates) then the whole system is unable to draw sufficient vacuum to fully operate either vacuum actuator Unit. 
 

The vacuum pump itself (operated off the engine auxiliary belt I think) also operates things like the brake servo and loads of other flaps and valves on the engine. So assuming your brakes are working fine, and your engine is too, then it’s most likely not your pump. 
 

typically it’s either the solenoid actuator in the engine compartment (a £25 part) or the vacuum actuator units on the rear muffler. 
 

I think I’m heading towards a design tek unit at half the price of Porsche OE. When I get it and fit it I’ll post the result on here. 👍🏻

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Many thanks. Breaks and everything else is working just fine so must be a leak from the actuator as you mentioned. 

 

Heading towards design911👍

 

Here's a short video of the rattling noise.

 

👍

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That’s just like mine sounded before it finally ‘gave up’. Sounds like intermittent vacuum pulling on the actuator diaphragm, which would explain the ‘fluttering’ of the butterfly valve in the muffler which would make that noise. 
 

so I think yes, perforated / split diaphragm in the vacuum unit / valve actuator that sits outside the muffler. 
 

I called D911 yesterday to ask about the quality of the design tek units (I’m happy to not fit Porsche OE parts if the alternative is equivalent or better quality (eg Meyle, Sebro, textar etc)), and save myself the 50% ‘Porsche Tax’ 🤔. But their Parts guy is in holiday till Wednesday. So I’ll call again on Thursday. 

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A friend of mine had the same problem with his 981S which was a "5 min fix" for his buddy who's a car technician (not for Porsche). He used the part from D911 if I remember correctly and worked like a charm. 

 

However, the vacuum units seem to be placed a bit tougher on the 987. But since you should only need to unplug the vacuum hose, loosen three screws and fit the new one, it should be pretty straight forward without removing the rear bumper. I also looked at a couple pictures of the 987 with the bumper removed and I'm not really sure if that would help. 

 

I think the best way would be to detach the exhaust from the cats back, if it's not doable just with some skinny hands 👐

 

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