I have a 95' LS that's been having some cooling system problems, 140k miles on the car. So a while back the top of my radiator blew off. I replaced the radiator, replaced the thermostat + flushed and bled the system. A few months later, my high pressure hose to my heater core blew. I was thinking i didn't bleed the system right and there was some air pockets or something. Replaced the hose, flushed and bled the system again, and no bubbles at all this time. Now, I was driving home at night, a 2 hour trip, and all of a sudden my heater went cold like it did when I blew my high pressure hose, and my temp gauge started rising right as I get off the freeway. I had to pull off and turn off the car. Popped the hood and couldn't see where it was leaking from cuz it was dark out and I had no flashlight. Let it cool, drove about a mile before it got to half way, then stopped and let it cool again. I was then able to drive the next half mile to my house without a problem.

I was unable to check where the leak was the next day as I had to catch a flight outta town in the morning. I was gone for a week, moms said there was fluid leaking from it, but no evidence when I returned. I checked all the hoses in the front and there was nothing. A little bit of coolant around the coolant reservoir, but when squeezing the lower radiator hose there's still a decent amount of coolant in there that didn't leak out, so I would assume its not leaking from the coolant reservoir. I'm kinda tempted to fill the system with water since I'm just gonna have to flush/bleed it again anyways and see if I can find the leak after a short drive, but I'm extremely busy the next few days so that might have to wait.

I know the thermostat opens, and the cooling fan kicks on. I removed the A/C system from this car a while back, the A/C pump stopped working, and the entire A/C system was dry. The auxiliary belt snapped so I figured I'd just yank the whole system out. Other than that, car gets its fluid changes regularly and still runs like a champ. Any ideas on what I should be looking for?