I have a cobalt ls 5 spd and out of nowhere even with the clutch to the floor when I try and put it in second over 20 mph it grinds gears. And now if I dont hold it in second when I let the clutch out it just pops out of gear, any one have any idea what this might be?

 

The synchros in the transmission need to be replaced. Basically, you need to have the transmission rebuilt or replaced.

 

I had the same problem with my third gear then my clutch started to slip would that be the same problem

 

the clutch slipping doesn't have anything to do with gears grinding. sounds like its synchros.... have to be easy on those gears. when you rush your shifting on a transmission that isn't made for it, it will cause this problem. more commonly the synchros from 2nd to 3rd will go first. the solution is to get it rebuilt. hope you have $$$$$$