Couple weeks ago I was driving to work and I heard a 'pop.' Was only a few minutes from work, car was still running decided to keep pushing on. Got to work and there was coolant everywhere. Got my girlfriend to pick me up after work. Couldn't look at it for a few days after that till I was there in the daylight. Filled it up with water, and noticed a crack in the top of the rad.

I was borrowing a car in the meantime so I was in no rush to fix it. Went to work one day and when I was away (When I go to work I'm outa town for about 36 hours) there was an unexpected cold snap. Dropped to -25 C or so (About -13 F)

When I got back I checked the car and of course the hoses and stuff were frozen. Being dumb I decided to add antifreeze and try and run the car for a bit to get everything thawed out/antifreeze mixed in so no more freezing. Was waiting for a day when I had time to get the car towed home. Everything seemed to start thawing out and I got almost a full bottle of anti freeze in there.

Got it towed home a couple days later, let it sit in the garage for 12 hours and changed the rad. Everything seemed to go fine. However now the car keeps overheating after driving it for about 15 minutes. Whenever it overheats the coolant is boiling outa the reservoir. I've burped the system a couple times. No signs of a cracked headgasket or blown frost plug. However, it seems that the lower rad hose doesn't get hot. (The top rad hose does)

Did running the car with frozen water in it ruin my waterpump? Somehow ruin the thermostat? Any help would be great!