No heat in my car

[Wes Tausend]

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Mike,

I thought of a couple of added tips.

The way to determine the "in and out" of the heater core is to note which heater hose connects to the bottom of the engine/pump near the main radiator hose that goes to the bottom of the radiator itself. This is the heater-core-out hose since this main radiator hose always draws coolant from the bottom of the radiator. Instead of the funnel/bucket method, I usually feed garden hose water back up this hose to blow out debris. Dirty water will flow out the other disconnected heater hose into a bucket if mess is a concern.

The debris is actually worse after you have run power-flush solution through the system after a long lack of attention, since it loosens up accumulated rust flakes from the engine block. In case performance noticably falls back off, there is often a bit more remaining system junk again "filtered out" by the heater core, partially replugging it again a week later. Tedious, I know.

To check the thermostat and possible excessive thermostat bypass leaks, feel the upper radiator hose (running) when the system has not yet come up to full gauge temperature. Only after the thermostat opens, should hot coolant flow into the top of the radiator, which may have an air pocket (and out the bottom which has a constant liquid supply to feed the waterpump).

If the thermostat and bypasses are operating correctly, there will be no significant hot coolant being wasted in the main radiator unless the engine is up to full temp. When thermostats fail (or are defective when new) they usually fail by staying open. A cold engine may impede heater operation, but may also trigger a computer to continue to run in rich mode, burning more fuel and carboning up the engine.

Nothing is more disgusting than a bum heater except maybe no-start.
I know a lot of guys here wouldn't recommend you feel your hose like that.
But a lot wood.

Wes


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