I have a coolant leak on top back fo engin. I checked the heater core lines and they are good. I see coolant comming out at the back maybe under the intake. Are there any coolant line that run back under the intake? 1998 Expedition, 4.6L
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Re: 98 Expedition coolant leak top back of engin
Sorry im late with this,i couldnt seem to log on....The answer to your question is YES,there is a steel line under the intake with a short piece of rubber line attached to it and you can just about see it from the front of the intake with a light,it can leak and cause coolant to run off the back of the engine,The intake gasket set alone is about $40.00 and i dont know about the rubber line,i have seen it physically but havent changed one yet.Note the date of manufactor just incase,i bought an intake set for a 99 and the engine design was changed half way through...its not too hard to pull off the intake and re-install,you will need a 7mm socket for the coil packs,8mm socket for the fuel rail bolts and lower intake bolts and power steering bracket bolts and throttle bracket bolts,10mm socket for the intake bolts and alternator bolts and egr valve,and a large cresant wrench for the exhaust tube thats connected to the egr valve,flat screw driver for the air cleaner...and plenty of extensions with a swivel to be able to get to the back bolts of the intake....just incase you do it yourself this info could make it easier to gather tools.Its about a 3 1\2 to 4 hour job start to finish for the first time doing it,includes cleaning everything..Good luck
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The problem is the heater core leaking behind the dashboard.
Heater CoreRemoval & Installation1997-2002To Remove: NOTE: Heater core must be vacuum leak tested before it is remove from vehicle if a heater core leak is suspected.
Drain engine coolant.
Remove instrument panel.
For 5.4L (4V), if quipped, remove junction splash shield.
For 5.4L (4V), if quipped, disconnect starter relay cable.
For 5.4L (4V), if quipped, remove junction block bracket.
Clamp inlet and outlet heater hoses.
Disconnect heater hose from heater core by gently pressing it toward heater core.
Remove A/C plenum demister adapter.
Disconnect vacuum line.
Remove 13 plenum chamber top screws.
Remove blend door assembly from case.
Remove heater core.
To Install: NOTE: If needed, clean and lubricate coolant hoses with plain water.
Install heater core.
Install blend door assembly to case.
Install 13 plenum chamber top screws.
Connect vacuum line.
Install A/C plenum demister adapter.
Connect heater hose to heater core.
Release all clamps from inlet and outlet heater hoses.
For 5.4L (4V), if quipped, install junction block bracket.
For 5.4L (4V), if quipped, connect starter relay cable.
For 5.4L (4V), if quipped, install junction splash shield.
IF the coolant leak is on the right side of the engine near the top of the trans,inspect the coolant hoses for the heater core. This is common leak point on the 98 exped. Thankyou Please rate this info
Fig. 7 Remove the A/C plenum demister screw and remove the
A/C plenum demister adapter
Fig. 8 Disconnect the vacuum line
Fig. 9 Remove the heater core bracket
Fig. 10 Remove the 13 retaining screws and remove the plenum
Fig. 11 Remove the heater core
Disconnect the battery ground cable.
Drain and recycle the engine coolant.
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 any 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.
Remove the instrument panel. Refer to
If equipped with the 5.4L 4V engine, remove the junction block
If equipped with the 5.4L 4V engine, remove the bolts and
disconnect the cable ends from the starter relay.
If equipped with the 5.4L 4V engine, remove the junction block
Disconnect the heater core hose couplings.
Remove the retaining screw and remove the A/C plenum demister
Disconnect the vacuum line from the A/C plenum demister adapter.
Remove the heater core bracket.
Remove the 13 plenum chamber top retaining screws.
The heater core mission. As for discharging the A/C system, I would
like to state for the record that it is not necessary to discharge the
A/C system to exchange the Heater core on an 98 Expedition/Navigator,
just drain the coolant, remove the dash, open
up the box that house the A/C system core and the Heater core, remove
and inspect the blend door for cracks where it attaches to the
actuator, check the blend door actuator then cut the metal lines on the
top of the heater core off for easy removal, from the engine
compartment pull the heater core lines through the firewall for easy
disconnect and that is it, you are now ready to start the re-install
process. One thing I recommend is while you have everything apart
change the blend door actuator, especially if you see traces of where
the coolant was leaking in the box. 9 out of 10 times the coolant
leaked out through the actuator and it is just a matter of time before
the electrical circuitry in the actuator quits working leaving you with
no heat or only heat. Well moving on to other issues now that heat
works and spring is near. Good luck and install in reverse, take pictures with your cell phone to use as reverence on things you took apart and Merry Christmas.
Your auto is definitely loosing coolant and will overheat. Check your thermostat, hoses, belts, radiator cap and water pump. If you do not fix the leak or coolant circulation problem you can destroy your engine. The smell inside can be being picked up from the outside vent or it could be your heater core inside the ventillation area leaking (which could be your coolant leak).. If that is the case you will need to replace the heater core.
check closer to just underneath the firewall--it could be a smaller problem than a heater core--Ford 4.6--5.4 engines have a tube just underneath the intake manifold that the rubber hose goes bad and it will leak towards the back of the engine.Lets hope so-what i hear its very expensive to change a heater core in an Expedition.
Big Pain - Must remove entire dashboard.
Drain the coolant
Remove the Freakin' pain in the arse dash
Open up the box that house the A/C system core and the Heater core
Remove and inspect the blend door for cracks where it attaches to the actuator
Check the blend door actuator then cut the metal lines on the top of the heater core off for easy removal
From the engine compartment pull the heater core lines through the firewall for easy disconnect and that is it
You are now ready to start the re-install process.
One thing I recommend is while you have everything apart change the blend door actuator, especially if you see traces of where the coolant was leaking in the box. 9 out of 10 times the coolant leaked out through the actuator and it is just a matter of time before the electrical circuitry in the actuator quits working leaving you with no heat or only heat. When I replaced mine it was still working, but the electrical motor with the spiral gear was making a funny noise compared to the new one.
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