Overheating and heater blowing out cold air

2005 BUICK LA CROSSE

141,000 MILES • V6 • 2WD • AUTOMATIC

LINDA93

MEMBER
1 POST
FOLLOW

t started to run hot, I put some coolant inside because it was really low. started it back up and it started to cool, but when I started to drive it went back to running hot then cooled off again then went back hot and my heater is blowing out cold air. this all just started was doing good up until now.

Mar 1, 2020 at 12:34 AM

ASEMASTER6371

CERTIFIED EXPERT
52,796 POSTS

Good morning,

Did you pressure test the system to find out where the coolant is leaking?

https://www.2carpros.com/articles/radiator-pressure-test

It sounds like you have air in the system. From the low coolant, the air has settled in the heater core which is at the top of the system.

Try running the motor with the cap off at 1200 RPM and keep watching the coolant level until you get good heat. Then make sure the level is correct and install the cap.

I would also recommend replacing the thermostat.

https://www.2carpros.com/articles/replace-thermostat

Roy

Images (Click to enlarge)

Mar 1, 2020 at 2:52 AM