Heater not blowing hot air
#12
12-15-2006, 12:02 PM
#13
12-15-2006, 01:55 PM
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#14
12-15-2006, 02:03 PM
RE: Heater not blowing hot air
I had the exact same problem with my wife's car less than a month ago. Heat didn't come through the vents unless I rev'd the engine a good bit. I just drained the radiator and ran some superflush through it to clean out the system and then filled it back up with coolant. Heater works better than ever now. if you haven't flushed the system in a while you might want to try that.
#15
12-15-2006, 02:45 PM
RE: Heater not blowing hot air
Before you go flushing the system and yanking the t-stat, park your truck either on some ramps or on an incline. Open the radiator cap and run the engine. Your system could be air-locked. You'll know it when there is a mini-sputtering of coolant in the air. Be sure to top the system off at first and be prepared to top it off again when it burps a few times. I'm not talking a lot of fluid shooting out, but something has to go back in to take the place of the air that is holding things up.
#16
12-15-2006, 03:27 PM
RE: Heater not blowing hot air
I have a 96, a 97, and a 98 Ram. Only the 96 has good heat. Here is a list of everything I have done on the 97, you could do the same.
1. Check the heater hoses to see if the inlet and outlet are both hot.
2. I flushed the heater core, then hooked a garden hose directly to the heater core to check flow through the heater core, it was good
3. checked flow throught the radiator, it was good
4. replaced water pump, no help
5. replaced thermostat, no help
6. check vacumn selector, checks good
7. tried the run-on-steep-hill to get the air out of the system
Next I am going to pull the dash and check the blend door. The blend door routes the air across the heater core or across the a/c evaporator. If the blend door doesn't close off the a/c evaporator then you get luke warm air out of the vents. It is a major pain to pull the dash but it is all that is left.
My symtptoms are the same as yours Luke warm air, and only slightly better when increasing engine rev's.
I would suspect you have a blend door issue.
1. Check the heater hoses to see if the inlet and outlet are both hot.
2. I flushed the heater core, then hooked a garden hose directly to the heater core to check flow through the heater core, it was good
3. checked flow throught the radiator, it was good
4. replaced water pump, no help
5. replaced thermostat, no help
6. check vacumn selector, checks good
7. tried the run-on-steep-hill to get the air out of the system
Next I am going to pull the dash and check the blend door. The blend door routes the air across the heater core or across the a/c evaporator. If the blend door doesn't close off the a/c evaporator then you get luke warm air out of the vents. It is a major pain to pull the dash but it is all that is left.
My symtptoms are the same as yours Luke warm air, and only slightly better when increasing engine rev's.
I would suspect you have a blend door issue.