Coolant leak....sorta

No coolant in the expansion tank?

Some of these suggestions may sound strange.

Check the battery. Are the terminals clean and tight? It the top of the battery clean? Consider having it tested at your local autoparts store.

Check the alternator. Have it tested while the battery is being tested. Also look for excessive AC ripple.

Consider that if the battery is weak, power to the PCM may have been lost. If so, the PCM will forget the idle trim values. Expect the car to run rough or idle too slow (die) until the new trim values are re-learned.

OBTW, to speed up the re-lean time, idle the car for 1 full minute with your foot on the brake (AC off). Repeat for 1 full minute with the AC on.

Inspect the spark plug wells for moisture. The spark plug wells in the 4.6 SOHC point straight up. Any moisture on top of the motor is likely to be retained in the spark plug wells.

Check the fuel system. How about the fuel filter? What is the fuel pressure?

Consider having the coolant system pressure tested. The tester can be rented from your local autoparts store. This will answer the question about the condition of the coolant system once and for all. Further, if there is a leak, chances are you will hear it.

Is your floor boards wet? sounds like the heater core is leaking.
if so just bypass if heater is not needed

HurricaneJesus,

Are you certain that you topped up the expansion tank? No flame intended, on the contrary, I ask because this sounds like something that I might do.

HTH,

Chris

HurricaneJesus:

OK, good. You have confirmed that the expansion tank was filled.

What's the latest news? Is the level still dropping with no visible drips or pooling in the valley under the intake?

Chris