Heater

2001 OLDSMOBILE BRAVADA
111,000 MILES • 6 CYL • 4WD • AUTOMATIC
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CAROLYN NELSON
  • MEMBER
  • 1 POST
Heater goes from hot to cold and then hot again.
Feb 8, 2018 at 10:17 AM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
I need some general information to help. First, is the engine reaching operating temperature and staying there? Are you sure the coolant level is full in both the radiator and overflow? Note: Only open the radiator when the engine is cold. Next, if the engine is warm, coolant is full and there is no heat, feel both heater core hoses under the hood. Under normal conditions, both should be hot. I found a picture online which shows the heater core hoses. They are the two approximately 5/8" hoses which run to the firewall. Check those things and let me know what you find.

Additionally, here is a video from the owner of this site discussing the top ten causes for heater problems. I recommend watching it.

https://www.youtube.com/watch?v=SNRb6pSwYuU
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Feb 8, 2018 at 6:30 PM
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