i have a 99 gsr motor and recently have been having some cooling issues. temperature is increasing when on the freeway for about ten fifteen minutes. temperature decreases when driven at lower rpm but still stays kind of warm. i changed the thrmostat and the problem continues. can a radiator lose its cooling properties? any help would be appreciated.

 

next time you drive, check to see that your lower & upper hoses are different temperatures. One should be noticeably hotter than the other one.

I'm assuming that it's bled properly and full.