My girlfriends car is giving her serious problems, and I know zero about those cars. Its a 97 Z28 convertible.

This is what happened.
She was coming home from a long roadtrip and it ran hot. Couldn't see anything wrong with cooling system though. No oil in water...no water in oil that I could see.

Well....Last week she was coming home from school and she said it started rattling really bad from under the hood. She was less than a mile from home so she tried to make it home. She said the rattling got louder. As soon as she put on the brakes to make the block; it died. So she cranked it back up and it drove a few hundred feet just fine, but as soon as she would press the gas..it would rattle and as soon as she pressed the brakes..it would rattle.

She HAD to drive the car last night. It cranked up and drove off seemingly fine. But as soon as she pressed the brakes to stop at a stop sign...it died again and took a few minutes to start back up.

It has always been hard to start since she got the car last year.

 

Is it still running hot? Water pumps are prone to fail on these. Thats a pretty easy fix any do it yourselfer can do.

As for the ratling noise, can you get a better description from her? Comming from the engine? On first thought it sounds like engine bearings

 

The water pump could cause it to die?

 

Check under the car to make sure there is nothing leaking and Is the SES light on? And in the future if the car over heats shut it off as soon as possiable. Junking the heads will cost you more than a tow bill to get a wp put on it.