Heater does not work when the engine is idling?

2013 FORD F-350
188,457 MILES • 6.7L • V8 • TURBO • 2WD • AUTOMATIC
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JONATHAN CARINO
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The truck listed above has a6.7 power stroke. The heater is not working while idling, only works when RPMs go up. The thermostat is good was just replaced and the radiators for both systems were replaced.
Dec 28, 2022 at 9:48 AM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Hi,

It sounds like it is low on coolant. When the engine is cold, remove the radiator cap under the hood and see if the radiator is full.

https://www.2carpros.com/articles/car-heater-not-working

Let me know.

Joe
Dec 28, 2022 at 9:21 PM
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JONATHAN CARINO
  • MEMBER
  • 3 POSTS
the coolant is full and have done a vacuum fill to ensure no air is in the system and nothing, air is still cold, I forgot to add that at a certain point the coolant starts to rise excessively (viewing it at the degas bottle) and starts to overflow out the degas bottle.
Dec 29, 2022 at 5:59 AM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Hi,

Does that happen if it is overheating, or does it happen at any temperature? I ask because that sounds like a head gasket issue. If compressed air is getting into the cooling system, this can happen. Do you notice any air bubbles in the coolant?

Take a look through this link and see if anything mirrors what you see. Also, let me know if the engine overheats.

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

Let me know.

Joe
Dec 29, 2022 at 8:10 PM
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