Ok, my radiator is leaking like mad. I have no idea why. It's not the hoses, it's the radiator itself. As soon as I shut the car off (when the coolant pressure is highest), i can see a big drop about every 2 seconds comin down from what looks like around the weld where the lower hose nipple is.

What causes a radiator to spring a leak like this? I'm more curious than anything, I'm not gonna go n try to fix it, I'll take it to a shop or replace it. But yea, anyone know what makes a metal core leak? Thanks