UPDATE! Switchable Exhaust Won''t Switch

Hi All, I have a Spyder valvetronic switchable exhaust on my C4S but since jan/feb I've noticed it's not switching... I'm just getting around to having a look. So the electrics appear fine, when I press the key fob I can hear the relay switching in the control unit, just nothing seems to happen out back. I've got the bumper off at the moment and Ive checked all the hoses and connections, nothing obvious there.. So I'm down to two theories; - valves are seized.. not sure how to tell, I can't seem to move either actuator by hand but I don't know whether I should be able to.. I assume it's under spring tension but no idea how strong.. I've given them a dose of WD40 but nothing's changed. - vac pipe switching solenoid broken.. don't think there's a way of checking this Anyone had any experience of the valves in the mufflers seizing on this brand or any other switchable system? Any ideas welcome! Cheers Martin

If the valves are the same as the PSE then you should be able to move them by hand. They do seize, but it usually takes a while of not being used.

I did some troubleshooting on my 997 PSE when it stopped working. I would expect your system to work in a very similar way, so this might help - http://911uk.com/viewtopic.php?t=132422

Awesome thanks, yes it looks like seized valves... did you take the bumper carrier off to get access.. if so how did you reset the position..? I've not taken them off yet..

Not too sure what you mean by 'reset the position' :?: On the 997 you just remove the lights, bumper and heat shields to gain access. They only re-attach in one position. If you are referring to the resetting the valves... it depends on what is broken. I have seen a number of issues reported, including; Broken vacuum actuating arms Broken vacuum actuators Seized exhaust actuator flaps Vacuum pipes split / disconnected Vacuum solenoid faulty, etc.

Yes I meant the side heatshield / bumper attachment strip - assumes that had to be set as it controls the position of the bumper, but perhaps it just goes back in one place as you say.. I'll have a proper look.. I'm sure that's the case.. that's gives me good access to the LHS valve anyway so I can use that a trial problem finder

The bumper and heatshield can only go back on in one position... there is very little or no scope for adjustment if I recall. You won't need to remove the attachment plate. I was able to have a good go at seeing what was going on with the actuator just by lying under the back of the car and looking/reaching up, but for any serious maintenance the bumper will need to come off. Its an easy job.

Thanks - yeah bumper is already off, no bother.. I've got hold of a vac tester too and confirmed that post-solenoid is seeing good vac switching on/off.. so it's definitely valves. Fingers crossed nothing inside the back box..

Well... let's see if this works.. put some penetrant on and no joy so far, I'll keep blasting it with it. Not really sure which way it's meant to move but won't go at all yet...

For the exhaust valves to operate then they will need a vacuum to them .. this is normally supplied via an electric valve . To test you would put a vacuum to each of the pipes going to these valves to see if the actuator on the silencers works .. or indeed does not work due to it being seized or a vacuum leak . As both of these pipes are joined then a leak at either one will stop both working . Tool here to apply a vacuum .. https://www.ebay.co.uk/i/3240880922...-41853-0&mkcid=2&itemid=324088092259&targetid After testing with this you will know if its the electric solenoid valves or the actuators . You could in theory just suck at each pipe leading to the actuators .. a rough test but will help . A seized valve one side won't stop the other side from working .. only a leak will .

On the 997, that pin which you have oiled, goes right through the pipe and comes out the other side, it then acts like a butterfly valve. You can just see it in my photo below. You need to get some oil on the back side too... ooh err!

I had to remove the linkage at the nut shown, so that I could get mulgrips / pliers on the bracket to get it moving. Afterwards I packed it with some high temp grease, like Optimol. Good luck! :thumb:

Hadn't considered the back side so I will give that a whirl. Thanks.

Is it general consensus that it'll be the flap that's seized (red) rather than inside the vac chamber (blue)

It's unlikely that the actuator will have seized, but the diaphragm inside could have failed, meaning no vacuum.