I have a 2005 Chevy Cobalt, it will start up and can be driven around and then all of sudden will shut off, we have replaced the crank sensor, new battery and alternator coil pack etc, it seems as it gets hot it just shuts off, the temperature is not high either on the gauge so i dont believe its the heads and its not showing any codes, can anyone help its been 3 weeks the car has been down and its my daughters so you know how kids are.
Thanks
Nick

 

what happens when it shuts off? does it stall or lose electrical power?
what trim level is the car? Auto/Manual?

 

Try googling Cobalt randomly turns off. You will see that a ton of people have this issue.

Does the car start back up?

Is it hard to start?

Do the gauges go haywire before shutting off?

Did you replace the crankshaft sensor with an ACDelco part? (Don't use autozone/o'reilly CPS)

Have you ever cleaned the throttle body?

Could be a bad/loose ground cable.