I just dropped in a mishimoto alum radiator. I used a t splitter to solve the whole second cap thing, and refilled it with 50/50 subie coolant. Everything APPEARS to be hooked up right and solid, but as soon as I took her out for a test drive, the temp shot up past the 3/4 mark. I let it cool off, drove it home slowly, and the temp stayed just under half like it's supposed to. When I got home, she was smoking like there was no tomorrow. Checked for leaks and couldn't find anything obvious, but the resevoir tank was almost totally empty.
I only used 2 gallons of water/coolant and I need to get more based on some of the posts here about after market rads. I'm also going to pick up the actual pipe for the tank. Any other ideas? She was fine before, just had a small crack in the plastic seal. Now with a new rad, it's running super hot. The fans DO work for sure as well, so it's not that. What's the deal? Any advice?