2001 Dodge Ram Low heater output

2001 DODGE RAM
211,191 MILES • 5.9L • V8 • 4WD • AUTOMATIC
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JDM89
  • MEMBER
  • 2 POSTS
My heater has low output at idle. But when the RPM's are raised, the heater output increases. Possible causes other than the blend door, it works perfect. Also, truck has new thermostat, radiator and thermostat housing. Both heater core hoses get hot.
Nov 8, 2015 at 6:48 AM
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ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
most likely the heater core is partially clogged with debris. you can flush it out with a garden hose. work it back and forth until good and clear.

Roy
Nov 8, 2015 at 7:06 AM
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JDM89
  • MEMBER
  • 2 POSTS
This has been done twice. Burped the system 3 times. Previous owner replaced water pump back in January. This has drove me crazy.
Nov 8, 2015 at 7:08 AM
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ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
it still may be a heater core. if it is clogged enough and will not clear it will restrict circulation

Roy
Nov 8, 2015 at 7:10 AM
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JDM89
  • MEMBER
  • 2 POSTS
The water flowed out good and clear as, well, water.
Nov 8, 2015 at 7:14 AM
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