overheating on 2002 Lincoln LS

I have an intermitent overheating problem with my LS. The thermostat has been replaced and the cooling fans are properly working. This problem has been going on for about a year. I've heard of this problem with these cars, but have not heard of too many solutions.

Asked by for the 2002 Lincoln LS
You need to get your rad pressure tested by a rad shop sound like your rad is stop up