How do you unclog - flush a clogged heater core in a Taurus - Sable?

Answer 1

Assuming the temp gauge stays in the normal range (otherwise check thermostat and associated engine hoses etc). The heater core has a blockage, Check the heater core hoses that enter the firewall from the engine compartment they both should be warm after the engine warms up if just luke warm you have a heater core/hose blockage- remove the two heater core hoses that enter the firewall from the engine compartment. Remove the blockage by flushing the heater core with fresh water from a garden hose. You can flush the heater core by removing the inlet and outlet hose connections and then using a garden hose to back-flush the core. If you do this, you must be very careful as too much water pressure will cause the core to leak. No more than 18 lbs of water pressure should be used. Be careful or you will be replacing the core. This "Related Link" below is to a photo-tutorial on flushing the heater core in a 2000 Taurus

http://s35.Photobucket.com/albums/d170spock81132000%20Taurus%20Heater%20Core%20Flush?action=view¤t=01FTHC.jpg I had my cooling system power-flushed at the local quick oil change shop - I thought it worthy investment for $40-50 it cost.

See "Related Questions" below for much more on Taurus / Sable heating-cooling systems
You need to disconnect the 2 heater hoses going to it and hook in a garden hose first to one then the other and if you're lucky you will be able to flush the core back & forth. If it won't, take it to a rad shop that has a higher pressure flush. You are taking a chance of blowing the core with the more pressure you force through it. Not a good thing if it leaks as at that point the dash has to come out (gut it too the firewall, a days work) to replace the core and while you're in there you might as well change the A/C evaporator as well as they are side by side.

One of the more ignorant jobs out there.....


I never heard of a total blockage in a heater core. This means you have the 2 hoses off the heater core connections and cannot force water back through the return pipe? How much oatmeal was used to plug that leak?

My dad use to work on cars and last week we froze to radiator up and he can and thawed it out and this week we were going to replace the heater core and he said it look like it was blocked is all, we don't know what is wrong with it all i know is i have air and no heat but i can elimate the little door thing bc it will put out warm air but not hot air so the gauge is working correct and allowing the hot air to get thru if there was any we have had it looked at three times and nobody can tell us what is wrong the heater core doesn't leak either?????
Do not rule out the 'little door thing' - it is very possible the temperature blend door actuator motor is NOT working.

If you are gettting some warm air, but basically cannot adjust the temps, it's even more likely to be the actuator.

See "Related Questions" below for more, not only about the actuator motor, but also flushing a core, replacing a core, and an outstanding round-up of "no-heat" trouble-shooting and repair steps.