Replace it /repair it... 1997-2000 Ford Pick-Ups /Expedition/Navigator*** Caution ***Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink ant that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old. Heater Core 1. Disconnect the battery ground cable 2. Drain and recycle the engine coolant. 3. Remove the instrumental panel. 4. If equipped with the 5.4L 4V engine, remove the junction block splash shield. 5. If equipped with the 5.4L 4V engine, remove the bolts and disconnect the cable ends from the starter relay. 6. If equipped with the 5.4L 4V engine, remove the junction block bracket. 7. Disconnect the heater core hose couplings. 8. Remove the retaining screw and remove the A/C plenum demister adapter. 9. Disconnect the vacuum line from the A/C plenum demister adapter. 10. Remove the heater core bracket. 11. Remove the 13 plenum chamber top retaining screws. 12. Remove the plenum chamber top. 13. Remove the blend door assembly from the case. 14. Remove the heater core. 15. The installation is the reverse of the removal.
Heater core could be clogged.
At the heater core itself.
Leak in heater core. Replace core.
Corrosion.
You may have a clogged heater core, or a leak in the system somewhere. Take your car to a mechanic who can replace the heater core or diagnose the leak.
The heater core or a hose to the heater core has a leak. Hopefully it's a hose under the hood because it's a very involved process to get the heater core out.
heater core has a leak replace heater core
Broken or split hose Radiator leak heater core leak
No, it's not normal. You have a leak in the heater core or may just be connections to heater core. If left untreated, it will soak into your rug and eventually cause your floor to rot.
heater core leak
you can try radiator leak stopper, but i would just replace heater core .,eally cannot be repaired.
not any oil in your heater core although the heater core uses coolant coming from and returning to the engine so when damaged or being worked on coolant can leak under the dash and into the floor