tgavem

Philly_Lights

Right around there. It starts off around 1100 for about 25 seconds when cold and eventually drops to around 8-900. I have a 16 GTS.

volcanogts

Reviving a dead thread, don’t shoot me.

Had anyone else heard of this before? Once in a while my 958.2 2016 GTS randomly idles high around 900 rpm, exhaust is loud at idle too.
It seems to be random, fine then idling high. Just now it was idling fine, then idled up when at a red light and you could feel it lurch forward a bit under higher idle.

About 3k mills ago the pcv valves were replaced, timing cover sealed, new timing guides and tensioners, plugs have around 15k on them probably.
any ideas?

I forgot to add, no codes at all. No smoke, no other symptoms, although seems like oil cap is under a bit of suction. I bought new Porsche pcv from fcp, wondering if one is bad.

I also did the coolant line under the manifold with new gaskets. Very odd that it’s intermittent but runs totally fine and then if you switch the a/c on or restart it’s fine.

Whitegalaxie

Mine does the same if I refuel with the engine running. Always. If I shut off and restart then all is back to normal and stays that way until I refuel while running again. Seems to me more of a function of the evap system than PCV valves.
When sport plus is enabled the rpm raises to 900 rpm. When deactivated it should drop to 800 or less rpm

volcanogts

You know what, now that you say that, it might be related after getting gas. I do always shut the engine off though.
Very good point, I am going to have to pay attention to see if it does it again the next time I fuel up.
If it does it again after I get gas the next time.

garrett376

Isn't the sport exhaust actuated by engine vacuum? So if there is a vacuum leak in the sport exhaust actuation system, the system will not be able to close the valve (be loud) and cause an engine to idle high/poorly.

Norge911

It’s part of emission if cat temperature is too low, it will idle higher to ensure emissions are per CO2 sensor settings.