It couldn't have been debris from the hose cause the fan rub off on the hose until there was a little hole where coolant would just be spraying under pressure(when at oper temp). No I didn't use rags to block any holes, I cleaned everything perfectly before installation. (not a messy diy, lol). The only thing I could think of right now us that aux pump. I'm not too sure what exactly is it's function and how it operates. What do you think?