I have a 2007 997.1 - 4S with a little over 84k miles. About a week ago (or 2) I started noticing primarily in 3-5 gears around 4000 rpm I get a short lag when accelerating. it is as if my acceleration stops for a quick second and then resumes. I have it at the indy now and while they were able to replicate the issue, they cannot figure out what is wrong. They checked one of the spark plugs and said they look good (probably changed about 20K miles ago). There are no codes being thrown. Nothing new has been added to the car (Gundo hack 5-6 years ago) - no other mods. The Indy said there is a software that can be updated and I told them to Change the Engine Air filter.

Any suggestions? I cannot believe my Indy is just throwing up their hands. Picking the car up in a few hours.

 

Clutch slipping perhaps? Do RPMs rise during the acceleration lag?

 

Just got the car back.......They Indy is telling me my clutch is going as it showed more signs this morning when they took it for a drive when it was cold. @semicycler good diagnosis. BTW- RPM i thought dipped a little (100-200RPM) and then picked up.

 

3,800-4,000 RPMs is right where the variocam plus kick in. I wonder if your solenoids that move the lobes are getting lazy. They should be able to check something with a Durametric tool to test them like camshaft deviations or another value.

 

@Petza914 I thought I read that if there was an issue with the Variocam I should have gotten a CEL.

 

Usually, but sometimes it takes a few instances of a problem before the car throws the CEL even though you can feel it doing something different before hand.