You can purchase a coolant flush kit from your local auto parts store for less than $10. It comes with directions.
You don't have to but it is a good opportunity to flush the system.
Clean the reservoir and flush the cooling system.
A flush and new coolant is not a bad idea on a 7 year old vehicle - pressure test system to determine if there is a leak and if so where
pull the handle down
Every 5 years
11.7 quarts
It uses Dexcool.
11 to 12 qts depending if it has ac or not.
2001 Buick Century coolant system repair costs
It would be best to go to bgfindashop.com and get a repair shop to do it for you. With the BG flush there is a cleaner put in and then the system is back flushed. The new coolant is added with a rust inhibitor.
Low coolant in the system. Defective heater control valve. Clogged heater core.
you might need a machine but what i do is disconnect a big hose from the raddiator thendrain into a pan refill and burp all the air out