FireHouse1

I have a 2009 997.2 C4s Manual and feel a slight hesitation at around 3k rpm when traveling up through the RPM range slowly. I really only notice this hesitation and very slight noise which I cant identify while in 1st and 2nd gear..
Car just broke 45K miles. I am getting ready to do plugs and coil packs shortly. Thoughts??

Bruce In Philly

2009 C2S MT 114K miles

Welcome to the club! I call it a 2700 thump, hesitation, dropout, miss... goes by many names. This has been a big enigma for many of us.... some have it some don't. Plenty of threads on this... appears to be more prevalent with 2009s but that is just my guess. You will notice it more if you are slightly accelerating going up a rise. I can get it in higher gears at highway speeds........ stay in a higher gear, like 5th, then let the car slow to where the RPMs hit about 2K or just below (the variocam will reset), then apply light gas and accelerate..... thunk....

My Ford friend (engineer at Ford, now on the Service Side) felt it without me saying anything "ah...what was that?".... he said that is usually a software issue.

It appears to happen when two things happen at the same time, with exceptions. Both the vario cam is transitioning to high lifters and the little plenum flap in our S air intakes are flipping at the same time (with windows down next to a wall, you can hear a "pshhhpt" as the plenum valve is actuated by a vacuum..... so is the assumption.

I have had this charm since I purchased my car new to me with 26K miles on it and now with 114K, I still have it. I took a drive with a Porsche dealer tech and he noticed it... said he heard of it but Porsche says nothing.... "keep an eye on it" .... great. I have a Durametric and the engine does not throw any codes.

Some with a base model, no plenum flap, also experience this dropout.

I posted this on RennTech... the tech there thinks it is a "lazy" actuator.... I posted this same question on the PCA website with no responses. I even had the Porsche dealer re-load the engine management software back into my car hoping there was a software update..... it may have helped but not really.

In short, if you figure it out.... post please. My next plan is to swap out the actuators at my next plug change at 120K (about $200 in parts).... there are two actuators, one per side, located between the plugs. Other than this hail Mary pass, I gave up.

Peace
Bruce in Philly

rherring

I experience the same behavior at around 2800 RPM, under light load and a slight upgrade. My car is also a 2009 C2S with about 33K miles. As best I can remember, it has done this since the car was new.

FireHouse1

well I feel better knowing that this is not something specific to my car. Thank you guys for responding to my original inquiry!

Bruce In Philly

You touched a real nerve with me.... this is something I think is pretty lame.... why do some get it and others no? The cars are all supposed to be the same.

Peace
Bruce in Philly

96Tiger

2009 C2S, 23,000 miles. Same hesitation, mostly in second, sometimes third.

Hella-Buggin'

My 997.1 has the same thing. I've read it's related to the vario Cam.

FireHouse1

hopefully someone has a solution.

DC911S

My FVD tune got rid of it in my 997.1. Not sure I feel it in my 997.2

speedracerf4i

My 2009 4S has the same hesitation at 2900 rpm too. I am so glad that's not exclusive to just my car. Not ill wishing, just relieved that I am not having problems.

ghostcow

Uh, yap, 2009 c2s with 30K, and I have had the same little personality trait since I got the car about 10K miles OK. Runs great otherwise.

Dripola

My 997.1 had it prior to and after an engine rebuild.

Robocop305

I don't have it on mine.

Shred

Just to say I have the same thing. 2009 997.2 C2S manual.

ChicagoSpeed996

Same thing here, though the FVD tune got rid of most of it.