mcipseric

Hi
My 2016 GTS is not sounding correct. The initial start up bark and pop is missing. There are far less engine over runs in sport mode.
No CEL or codes.
Wondering if anyone here has the same issue?

thanks

Jim137a

Jim137a

mcipseric

^^^thx!^^^^

matttheboatman

I recall thinking my GTS was sleeping on the job at times. But, it may be that you have not been driving it aggressively enough lately? The ECM does learn your driving style. The pops are created semi-artificially by the ECM adding extra unburned fuel to the system. So, if you take to the highway and floor it so it gets to near max RPMS in each gear, when you brake and fires down through the gears it should sound like a GTS. If not, you have a problem. And, the good news of waking up your car is that the next time you drive to the grocery store, even a slight lift after 3,000 rpms will provide the symphony of exhaust sound you are seeking.

mcipseric

Just tracked her. still same issue.

I recently lowered the car and I am thinking the lower distance to the ground is causing the noise difference.

vbb

I don't know what is causing the issue, but I know what isn't...your car being lowered should have nothing to do with why your exhaust isn't sounding like it is supposed to sound (unless somehow you damaged your mufflers).

ICNU

+1.
OP, Lowering the car has nothing to do with anything. It wouldn't matter even if the vacuum lines for the PSE were pulled off or damaged during the lowering or some other work on the car as the default valve position with no vacuum on the valves is in the on position. The worst that can possibly happen is the PSE is stuck in the ON position at all times which is the opposite of what you describe.

The aggressive cold start sound is due to the ECU causing the car to run rich and changing the valve timing temporarily in order to rapidly heat the cats, and then things quiet down after a few seconds. PSE button on or off during the cold start has zero effect on anything and the car will always sound the same for the first 45 seconds or so, but a warm start will not have this same initial aggressive sound. The off throttle crackle and pops wont start happening in full swing until things heat up to a specific level. On my car they start occurring when the water temp hits exactly 185F. My assumption is the exhaust just happens to be up to the needed temp at that point in the warm up of the car.

Since the default for the PSE is on, there really isn't any way for something to go wrong with the exhaust that would make it more quiet with the exception of the off pedal crackles which would require the ECU programming to suddenly change since the ECU is what is creating these fake burbles. In other words its virtually impossible for the PSE to just go quiet both electronically or mechanically. If anything it will be opposite problem.

There is one other thing though since you have a GTS, and that is the sound symposer valve that the GTS has and the normal Caymans do not which pumps extra engine bay noise into the cabin with a valve through a hole in the firewall behind the seats. Have you possibly done something or placed something behind the seat to baffle this sound coming in? Maybe you have become accustomed to this sound and now noticing a difference in the sound in the cabin?

mcipseric

the sound difference is external. the dealer did find a faulty valve and replaced it. However, is still is not the same sweet sound. I will ask the dealer to swap the entire exhaust system shortly and see if that fixes it.

thanks!

ICNU

Good luck with that! I cannot imagine any dealer swapping out a complete PSE based solely on someone's anecdotal claim that it doesnt sound right to them. Sound is very subjective, and exhaust systems are simple mechanical devices that dont just magically fail or change unless they are completely rusted or rotted out in some way. On the other hand, high flow cats on aftermarket headers can and do get clogged up and fail often, especially on tracked cars but that's a different discussion.

vbb

Any chance you can upload a sound clip or video so the rest of us can have a listen? I know what a PSE equipped 981 is supposed to sound like as do most of us here. I'm sure we could at least eliminate whether or not what you're hearing is something electronically/mechanically wrong or if you're just become "tone deaf" to the sound. I have never heard of a PSE car losing that throttle-lift, overrun pop and gurgle sound when the valves are working properly. If one of the valves was faulty and needed to be replaced, I'd definitely check to see if the other is having a similar issue.

Code

Stuck valve gets my vote.

ICNU

Once again keep in mind the valves are mechanically defaulted to the ON position and require vacuum to close them. Even if broken they will be in the on position at all times. I'm not sure how the PSE valves can be the cause when you must manually force them closed against spring like pressure and then mechanically tie it off that way to keep it closed assuming no vacuum.

You could completely remove both valves from the system and it would still be loud all the time just like any other non valved aftermarket exhaust is. It will be interesting to see what the final outcome of this issue is as the dealers claim of the "bad valve" just doesnt add up and seems placating to me just to make someone feel like they did something and hopefully go away while rolling their eyes behind your back.

mcipseric

Don't worry about that. I have a very good relationship with the dealer :-)

ICNU

Ok, cool because I know they would just laugh at me at me for such a request, but I see you are an instructor at the LA PEC so you have a few more connections than I do!