Coolant in # 1 cylnder\clean intake port of intake manifold

yes 15psi coolant can leak and spray where ever it wants, called squirting.
gee park the car hot, open the hood and look for 1hr. idling hot.
the leak will be found.???
by just looking, not casually , every inch there.
your valve cover and spark coil (COPS) has leak (coolant)
some cars with cops can have a seal at the bottom of the COP well..
if not good it leaks oil not coolant so are you confused on
green coolant over, brown oil?
and spray can not land and pass by COP top seals unless those seals are bad (a double failure this) and 21 year old.

2001 engine ford 5.4L.

"tested for cracked head/gasket 3 times"
combustion side and water jacket leak down test. both?

it seals the combustion chambers and independent COP WELLS
5.4 liter TRITON engine not super charged , correct?

this engine is odd for cops. not done center of valve covers
or plugs at exhaust ports, (no cop fits there ever)
so ford put the cops into the head, and the head gasket is bad there
or you have casting flaw to the cop well to the water jackets
one way to find this is :
clean the #3 well dry
then on cold engine
run it till hot, 180f to 200F and cut the engine at key
then pull #3 cop and with a flash light look down the well to see the now 15psi pressure pushing(green collant) in to the well
if seen to ooze from inside walls, that is a castling flaw.
or the intake manifold water gasket seal leaks and drains down the cop hole.
I have no xray view of the head or this would be a childs play answer, given that.,
not sure me what heads are here, SOHC or DOHC. 2 or 3 or 4 valves per cylinder. guess at SOHC 2v.
5.4L has many varants on heads. photos of your cops would answer all that.
are your heads F6AZ MARKED.

see this water jacket port on Intake MAN they can leak can to places not wanted.

RECAP[
BAD GASKETS RELATED HEAD/ AND INTAKE.
BAD HEAD CASTING FLAW
the cop boots on an car this old are no good, and cheap to replace.
like $15 a pop
clean them up and HV just hates, contam., here, clean it all.
use NGK plugs or AC not chumpions.< that love to break)
sure ford, parts , sure motorcraft.
sure.
here is the 3v head. see that wall there behind the cop,
forget cylinder numbers for now.
see this, coolant would have leak massive to go over this dam.
so what heads do you have? 3 kinds. (2 or 3 is possible) 4 not.










this is Mr.COP, see the red arrow
if the coolant is sitting above the seal , and cop is pulled out , it then goes down, to the spark end. and spark ends.
if there is head casting flaw it will leak seen car parked hot engine turn off and 15psi coolant pressure will leak at #1 intake runner
or in the well
one or the other, and is the cause when seen. and tested.

I had a 2000 malibu 3.1 and the manifold gasket was leaking. Model years affected, 97-04. Check the recovery coolant tank and if it looks like a milk shake instead of coolant, then you have a bad intake manifold gasket. I replaced mine a few years ago and all was fine. Engines affected are the 2.4-3.1-and 3.5, look very carefully around the intake manifold and you will see it if its leaking! operating the engine with a coolant/oil mix can result in internal engine damage. Replacing the intake manifold gasket should correct these leaks. Because oil will mix with coolant if gasket is bad. Hope this helps you out! Good-Day!

Intake Manifold gasket replacement fixed my very similar issue. New ones from GM are aluminum w/rubberized gasket - old ones plastic with a rubberized gasket - common failure in the 80-100k mile range. My mechanic did it for $620 included sealant,thermostat,valve cover gasket, gasket kit, coolant,pipe,pipe, manifold t and supercharger gasket.

Instructions

1. Removal

Unscrew the bolt that holds the negative connection to the Impala's battery. Set this bolt aside for later use.

Remove the engine cover to access the intake manifold and manifold gasket. Disconnect the throttle body inlet duct from the engine.

Twist off the radiator cap to allow draining of the coolant to flow more smoothly. Place an empty container beneath the radiator's drain plug, and remove this plug. Allow all of the engine coolant to drain into the empty container. Replace the drain plug once you are finished.

Tag all of the electrical wiring and hoses before removing so that reconnection is precise to factory settings. Remove these parts, individually, from the intake manifold.

Loosen the bolts that hold the intake manifold to the Impala's engine block. Lift the intake manifold from the block once all bolts have been completely removed.

Use the flat-head screwdriver to pry the old intake manifold gasket from the engine block. Discard this part once you have removed it.

Clean the engine block thoroughly with the engine degreaser and linen cloth. If necessary, use a gasket scraper to remove excess buildup and grime.

2. Installation

• Coat the top and bottom of the new intake manifold gasket with a chemical sealer so that it bonds to the engine block securely. Position this new manifold gasket so that it lines up perfectly with the cylinder ports of the Impala's engine block.

Place the old intake manifold on top of the newly-installed manifold gasket until it aligns with all of the holes of the cylinder flanges and manifold gasket.

Attach all of the bolts with your hand to the manifold. Once all bolts have been positioned, use a torque wrench and apply 15 foot-pounds of pressure to the bolts to secure the manifold into place.

Reconnect all of the necessary hoses and electrical wiring to the intake. Pour the engine coolant back into the radiator.

Reattach the engine cover on top of the intake manifold and engine block. Start the Impala's engine and check for any leaks around the new intake manifold gasket.

I will offer a possible solution. There was a change in the intake manifolds because of soot buildup. On the old design, 8 bolts hold the airhorn to the intake manifold. Under the airhorn, and under its gasket is a channel which needs to be cleaned for top performance.

It takes a $10 gasket, and about 1 hour of time to pull and replace the cleaned part and to clean the intake passages below the airhorn.

This may be your problem.

To install:

1. Clean all gasket surfaces completely.
2. Install the intake manifold gaskets with the port blocking plates facing the rear of the engine. Factory gaskets should have the words "This Side Up" visible.
3. Apply gasket sealer to the front and rear sealing surfaces of the engine block.
4. Apply a 0.197 inch (5mm) bead of RTV sealer to the front and rear of the block. Extend the sealer approximately 1 / 2 -inch (13mm) onto the heads.
5. Install the lower intake manifold.
6. Apply sealer to the lower intake manifold bolts prior to installation.
7. Install the bolts and tighten in sequence and in 3 steps as follows:
   1. First step to 26 inch lbs. (3 Nm).
   2. Second step to 106 inch lbs. (12 Nm).
   3. Final step to 11 ft. lbs. (15 Nm).
   
   
8. If removed, install the alternator bracket bolt.
9. Install the coolant by-pass hose.
10. Install the EGR valve.
11. Connect the upper radiator hose to the thermostat housing.
12. Connect the heater hose to the lower intake manifold.
13. Connect the fuel pressure and return lines to the lower intake manifold.
14. Connect the wiring harnesses and brackets to the lower manifold.
15. Install the throttle cable bracket, then attach the throttle cable and the cruise control cable (if equipped).
16. Install the transmission oil level indicator and tube, if equipped.
17. Install the EGR tube, clamp and bolt.
18. Install the PCV valve and hose.
19. Install the A/C compressor and bracket.
20. Install the distributor.
21. Install the upper intake manifold.
22. Fill the cooling system.
23. Connect the negative battery cable.
24. Start the vehicle and check the ignition timing (not adjustable).
25. Verify no oil, coolant, vacuum or fuel leaks.

    

26. Install the intake manifold bolts and tighten them to 35 ft. lbs. (48 Nm) in the sequence shown.
    

change the plug wires they may be bad. or you may have a bad coil

heaterhose is in that general area. most common leak is that spraying aroung so it looks like something worse