The title sounds a lot worse than reality in this case!

I was taking my C4S down to the shore house last week, and about an hour into the drive a big yellow "Coolant System Fault - Visit Repair Shop" message popped-up. Needless to say, as I am cruising along at 80mph down the A/C Expressway on a hot summer day, with maybe another hour to go (with a possibility of getting stuck in stop-and-go shore traffic) I was alarmed and quickly debating whether I should pull over, stop driving and call Roadside -- or keep moving to maintain airflow... and ignore the warning.

So I flipped over to the car vitals, and checked the temperatures. All looked normal. Water, oil, everything within acceptable limits. I also didn't feel any difference in performance, see any smoke, etc. So I just kept driving. But the whole rest of the ride I kept a close eye on the temp gauge just in case we started getting into the red zone. Nothing ever happened.... Phew!

So every time I start the car up after that day I get the same warning message... and nothing ever seems abnormal (or so I thought). I wait until Monday this week to take the car over to the dealer....

Turns-out that the problem was a vacuum line hose connected to the exhaust valve had come "loose"! Wha? Never in my mind would I have associated a warning like "Coolant System Fault" with the open/close valves on my exhaust! My SA explained to me that this is because there are a lot of interconnected lines, and are associated with our infamous change over valves....

Oh well, glad it wasn't something worse! They re-attached the hose, tightened the clamp, and all was back to normal. Except.... I recall afterwards that my non-PSE car has been sounding exceptionally more "throaty" over the same period, and after they fixed the loose hose my car just purrs instead of growls. I guess the exhaust valve got stuck in the OPEN position regardless of engine speed so I effectively was hearing the PSE... !

 

Glad all was well! Hope you enjoyed the Joisey shore!

 

My 14 4S also got it last week. Still drove about 1k with it, temp was fine. I do have PSE. Was at the dealer today for my first service. Waited 2h. Then they said to fix this issue it would take another 1.5h. After another hour they said they missed a part... and i had to come back tomorrow. So waited 3h for nothing. But hey, it's Spain.... and they are retards here. Hope its fixed correctly tomorrow.

 

Right- the "S" models have the exact same exhaust configuration for the most part where the vacuum lines are involved. Just PSE comes with the switch to manually open/close the valves, whereas a non-PSE care like mine doesn't -- the valves only open over 4k RPM.

But curious what part they need? In my case they just tightened the hose connection with a small clamp. Do you mean then need to change the Change-Over valve that many of us on this board have had issues with?

My SA mentioned to me something interesting, that I've also heard elsewhere on this forum... that the root cause in my case and in other cases they've serviced is that the vacuum hose is stretched to the limit and without additional clamping will wiggle-free enough to cause my problem. In this particular dealers service dept opinion, Porsche factory should have made the lines just a few microns longer for more tolerance to changing conditions.

Good luck!

 

Exact same thing happened to me. Dealer asked if I removed the hose as "they never come off." A few months later there was a service bulletins about it and some fix was applied.

 

Glad you got it sorted.

Curious if you could describe the sound it made before fix a bit more? I do not have the fault on the dash, but my non PSE C2S car has developed a droning that wasn't there before. It sounds about the same as a fully open sound symposer, except at all times, including in non-sport mode, when the symposer is supposed to be off. I have plugged my symposer and even tried disconnecting the tube, but sound is same, so I don't think that is the culprit.

It is due at dealer next week to test the changeover valves, so I am hopeful it may be as simple as something like yours -- except I don't have a dash error message....

Also, did yours quiet down on startup after initial warm-up phase? Mine does, which I took as a sign that the exhaust valves are working, but what do I know?

 

I would describe the sound as a constant, deeper, throatier sound in all gears, regardless of engine speed/RPM. I've driven 991s with both PSE and aftermarket exhausts, and to me this condition sounded a bit like PSE, but not a full-blown aftermarket. It was noticeable especially on downshifts, all the way down to a stop. Prior, the car just purred nicely when downshifting after perhaps an initial pop or crackle if I was dropping-in from light speed...

As for start-up - yes, it was noticeable then as well. My car would start rough, then would quiet down a bit -- but nowhere near as much as before the hose came loose. Funny thing is I liked it! So even though the thought crossed my mind that there was something different happening, I just let it be until I could get to the dealer. Now that it is "fixed" I'd rather have the deeper sound back, even if it droned a bit on the highways (I don't drive enough to have that bother me very much at all).

Anyone know if I can just disconnect the hose lines from the valves, cap them so I don't get any warnings?

Oh, and remember -- many of us on this board who have experienced change-over valve issues of various types never received any warnings, messages, or fault codes at all....

 

Its been fixed. Dealer replaced a part. Not sure what exactly.

Car runs the same (good), same sound. Only the error msg is gone.