i had same problem in my 2007 as well
what i did was
drained all the radiator exsisting coolant , flushed all the circuit with water, refilled in and added 10 min radiator flush in it ran engine with car stationary for like fifteen mins or so, drained the water completely and added fresh coolant again, so far so good.
this is even affective if u have a partially chocked radiator, flush the circuit with the help of water pump centrifugal type plus make sure that pump doesnt make too much pressure as it can impact ur gasket.