I have a 2008 mustang GT. Car has a 5 speed manual transmission. I was going down the road yesterday and tried shifting gears and it would not go into any gears while the car is running. When I shut it off I can put it in gear start it up. It doesn't lunge forward or anything when I do this. I have put the car on a hill and shut it off and put it in first and depressed the clutch and it does not roll back. Any suggestions on what is going on?

 

Sounds like the clutch is bad or out of adjustment. May need a fluid change and bled.

 

But with it being a hydraulic clutch system. It is self adjusting. And the fluid run directly into the brake system. Right..

 

The fluid could need changing and bled. The fluid gets old and depending on the miles, can be very dirty. New fluid and bleeding would do the same as adjusting.... A lot of times, one can shift gears without the engine running AND without touching the clutch pedal so that is not really a test for a good clutch.

 

Your clutch is toast.

 

your clutch is not disengaging. possible the clutch master cylinder or slave cylinder is leaking.