Why won't my 911 carerra 4s turn over?
The first thing I would do is check the battery, they tend to only last around 5 years on average. I would also check the battery in the key fob, as it can keep the car from starting if its not getting the signal from the key. If you have a second key you could try that as well. let us know what happens and if you need any further help.
If it is a stick shift manual, likely that the clutch pedal switch is bad. These are about $20 and very easy to replace yourself. You don't even need tools. If it is either a stick shift manual or tiptronic, could be either the clutch pedal switch or ignition switch is bad. Ignition switches are under $40 and are a common fault. Not as easy to change as the clutch switch but easily a DIY job.
Search Porsche 911 Questions
Porsche 911 Experts
Related Models For Sale
Used Cars For Sale