I have a 2007 Grand Prix that's overheating
May want to do a super cooling system flush also would not hurt to spray out the radiator to clean off dirt and bugs so that you can get better air flow across the radiator fins.
Do you think I should change the thermostat as well
Did not mention that because I thought you would have done that already but yes replace thermostat.
The replacing of the thermostat maybe all that you need to do.
Looking for a Used Grand Prix in your area?
CarGurus has 3,715 nationwide Grand Prix listings starting at $879.
Search Pontiac Grand Prix Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Pontiac Grand Prix Experts