Heat comes and goes

2002 PONTIAC MONTANA
160,000 MILES • 3.4L • V6 • 2WD • AUTOMATIC
Avatar
LONELYREDNECK85
  • MEMBER
  • 1 POST
flushed heater core then had heat for one day and now overheats.
Jan 3, 2018 at 5:29 AM
Advertisement
Avatar
STRAILER
  • ✓ASE Certified Mechanic
  • 54,837 POSTS
  • ASE Certified Mechanic
Yes, it sounds like you have a blown head gasket which fills the heater core with exhaust gases causing the heater to stop working.

Here is a guide to help you confirm the issue:

https://www.2carpros.com/articles/head-gasket-blown-test

Please let us know what you find. We are interested to see what it is.

Cheers, Ken

Jan 4, 2018 at 3:06 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.