Sport exhaust failure

[seahawkeye]

Has anyone had any problems with the sport exhaust failing (without and indication lights)? Does tracking damage this temporarily?

Brief history for my car for perspective: bought my 2007 C4S with sport exhaust and sport/chrono package as a CPO 2 years ago. The sport exhaust didn't work when I bought it so dealer tried to fix it but didn't work still so they fixed it again. Since then, it worked the vast majority of the time except after my first two track experiences (which by the way were incredible in this car!). I noticed that by the end of each track day I could not hear the sport exhaust anymore and was uncertain whether the sport button worked at all. Each time it fixed itself despite a trip to the dealer several months ago to investigate before CPO ran out but they found nothing wrong.

Should I be worried? Is it normal to temporarily go out after tracking? It's already been fixed twice by the dealer pre-tracking...

[Loren]

It is a simple vacuum system that opens (or closes) two mechanical valves using engine vacuum.

Chances are one of hoses comes loose or you have a weak switch-over solenoid.

[jfoxny]

Has anyone had any problems with the sport exhaust failing (without and indication lights)? Does tracking damage this temporarily?

This happened to me over this past weekend during a long trip. After being parked on the top of a parking garage overnight (in the hot sun) the PSE wouldn't turn on. I've been having other electrical issues with the car so it might be related - not sure yet. I am going to bring it into the dealer next week. I will post what they find.

[seahawkeye]

Loren, is this something that would be an easy DIY fix or should I suggest this to my dealer?

jfoxny, sorry to hear this happened to you too, would be interested to know what they said

[Loren]

Could be as simple as a vacuum hose vibrated off of one the valves.

You should check those connections.

(click to enlarge)

[jfoxny]

Could be as simple as a vacuum hose vibrated off of one the valves.

You should check those connections.

(click to enlarge)

pse.png

I checked my connections yesterday and they were fine. I also pulled the orange plug to see if that would "activate" the PSE but it did not. Does that indicate a solenoid or vacuum actuator failure?

[Loren]

If you reverse the check valve and it does not actuate them you likely have a leak.

The solenoid is just a twelve volt solenoid so you could test that independently. If the solenoid is okay then your next route back would be the relay.

[jfoxny]

Has anyone had any problems with the sport exhaust failing (without and indication lights)? Does tracking damage this temporarily?

This happened to me over this past weekend during a long trip. After being parked on the top of a parking garage overnight (in the hot sun) the PSE wouldn't turn on. I've been having other electrical issues with the car so it might be related - not sure yet. I am going to bring it into the dealer next week. I will post what they find.

Problem turned out to be a failed Vacuum Actuator Unit (Bank 2) Part #997-111-680-00.

[anthonycocca]

997 C4S same problem. vacuum actuator had to be replaced only 21k miles on the car........

[seahawkeye]

Well, my sport exhaust went out again after tracking my car--this seems to only happen when i track it!

 

This is the 3rd time it has gone out now, and the dealership can't seem to get a permanent fix on it. Here is brief part replacement/history:

 

2011: R sided exhaust diaphragm leaking so was replaced (under CPO as this was right after I bought it)

June 2013: sport exhaust went out after tracking car but spontaneously recovered so nothing replaced

Oct 2014: solenoid was replaced after road america track days killed it

Oct 2015: nonfunctioning again after blackhawk farms track day (driven <1000 miles since Oct 2014). I did hear a 'doin-gggggg' like a spring coming loose as I was making a corner so not sure if this is what broke it or not

 

My questions:

1) it seems these cars commonly have sport exhaust failures--is it impossible to permanently fix it? i.e. is it worth paying $$$$ out of pocket to fix it if it might just go out again?

2) how difficult is it to diagnose myself, like using Loren's diagram? I am unfortunately not that handy with DIY but could go back a jack if that's helpful. could also bring to local indy/friendly dealer to put up on jack but will I be able to find the problem easily?

3) is it better to just be a new sport exhaust entirely and if so, which one would be recommended--a louder one than OEM would be ideal!

[Rikky]

If the vacuum hoses are off the exhaust flaps are open. You need vacuum to close the exhaust flaps.

A permament fix, if you wish to drive with open exhaust all the time, is to pull the vacuum hose off.

I suspect more that your actuating mechanism (mechanical part) is seized, as you heared a kind of spring sound? Check your mufflers if the levers from the actuators move freely.

[Orient Express]

The default mode for the PSE is on or "loud".  That can be set by simply removing the vacuum lines from the mufflers and plugging the lines, or disconnecting the electrical connection to the solenoid.

[seahawkeye]

Thanks for thoughts--how do I remove the vacuum lines from the mufflers and plugging the lines, or disconnect the electrical connection to the solenoid?

[JFP in PA]

Thanks for thoughts--how do I remove the vacuum lines from the mufflers and plugging the lines, or disconnect the electrical connection to the solenoid?

 

The valves look like this: 

 

 

The small black appearing tube sticking out to the right is where the vacuum line would attach.  There is one on each exhaust system bank.

[Rikky]

A picture says more than words!

Start from there in the troubleshooting - check if the rods are moving freely.

 

If they move freely than there are only 3 options why your exhaust flaps do not work, either the solenoid valve does not work, there is no vacuum to actuate the actuator, or the actuator itself is broken.

As already mentioned, the default mode is loud; either pull of the vacuum hose or the solenoid valve connector - this should open the flaps.

 

If you exhaust flaps stay in closed (silent) position with the solenoid connector removed or the vacuum hose of, then the problem is either in your exhaust - flap(s) seized or actuator(s) seized in closed position.

These actuators are simple things, the rod is out when no vacuum present and when vacuum is applied a membrane will pull the rod in - and close the flap.

 

Let us know what you find, easy to check.

[Rikky]

Just curious; could you find out and fix your problem?

[racerken]

@Seahawkeye:  I had similar issues.  In my case there were vacuum leaks in the line between the solenoid and vacuum actuator.  when the motor was out, i took my time to trace all lines from the vacuum actuator to the vacuum source.  i can see that there is rubbing of the line between the vacuum actuator (VA) and solenoid (which is located on top of the motor behind the throttle body.  the line is protected by a stainless steel mesh which can rub against the muffler support assembly (you should see clips) then transitions to a plastic line just outside the intake manifold runners.  

 

P1060005 by racerken, on Flickr

 

See the braided line?  Every location where it comes in contact with metal causes wear and of course vibration helps to cut thru, heat causes the plastic to become brittle.  Just replace it but it's really expensive from the dealer.

 

I have more pictures if you want.

 

[seahawkeye]

Thanks to all for the suggestions, I've been out of town so haven't been able to look yet. The pictures are most helpful. @raceken your hi res pic is nice but I'm a little disoriented since everything is out of the car body--do I have to remove the engine from the car to find what you're referring to?

 

I don't mind having the sport exhaust on at all times. But I wonder whether I just need to get a new exhaust (maybe non OEM that is louder?). Will check car this weekend to see what is up so I can report back!

[Rikky]

Just stick your head under, you will be able to see this; don't drop the engine.

[racerken]

NO, DON'T Drop the engine.  I had to drop it because of the Air Oil Separator...  

You can remove the heat wheel well and heat shield to get a view of the vacuum lines.  you can also hook up a vacuum tester that when plugged into the vacuum line, creates a vacuum and there is a guage that you can monitor - if the vacuum drops, you know you have a leak.  Lead detection is not easy and there is no short cut or 'easy' button.  

 

If you go into my flickr page you can see all sorts of engine shots.