No heat from heater

Maintenance/Repairs
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1

I have a 1995 Dodge Caravan 3.3 liter. I cannot get any significant heat from my heater dour the winter. I have done the following things so far to no avail.

1. New water pump (it was leaking)

2. New thermostat

3. Checked in line vacuum operated water valve

4. Checked radiator cap. System is under presure.



Any ideas as to what to do next?



Regards,



George

Pennsylvania

2

Since you’ve had cooling system open, you have to make sure there’s no entrained air in the cooling system. To remove any air from the cooling system try this.

Get the engine up to operating temperature. With the engine idling, loosen the upper radiator hose clamp. Take a small flat bladed screwdriver and insert it between the upper radiator hose and the radiator hose neck so it opens up the cooling system. Let the engine idle until all that comes out of the upper radiator hose is coolant. Remove the screwdriver and retighten the hose clamp.

Tester

3

If the air purge that Tester describes doesn’t work, you may have a plugged up heater core. You could try to flush it out with a garden hose.

With the engine cool, remove the two hoses to the heater core. Use one hose, and connect a garden hose female connector so you can attach a garden hose to it. Put the other end in a collection bucket. Turn the hose on just a crack. You should hear the water run. If the core is not plugged, the coolant should push out of the core as water is pushed in.

WARNING Do not let the water from the garden hose run full if the core is plugged. The water pressure from the house is greater than the design of the cooling system, and letting this house pressure build could blow out the core inside the van. It’s much safer to remove the core and flush it if it is plugged up.

4

Thanks! Will give that a try.

5

Here’s how I remove air from an automotive engine system. Pull up on a steep driveway with a cool/warm engine. Carefully remove the radiator cap. Let the engine run to operating temperature. Slowly fill with anti-freeze (not water). When the radiator remains full-replace the radiator cap. The air will have escaped through the open radiator and your heat will return.