well I got my engine back in again, idled it for a minute or so and now I put coolant in it. Coolant is weeping, very slightly, from the rear driver's side corner; right at the corner. Is this unheard of in a rebuild? I am hoping when I go to actually driving it the gasket will seal and that will be it. Failing that, what kind of system sealer goop do you guys recommend for small leaks like this? Dad says he's heard of something bmw uses that is composed of powdered aluminum.