I have a 2004 expedition 5.4L V8 Eddie Bauer. I had a crack in my intake manifold and replaced it and the gaskets. I now have a steady dripping coolant leak that appears to be coming from the back of the motor. If you are looking down at it from the top you cant see a leak but looking under you see the drips coming down. I took the manifold out and checked my gaskets and they still look new. I checked for cracked head and found nothing. It looks like I had a leak from the back screw on the right (drivers side) like my screw wasnt seated down all the way to make a tight seal. I cleaned everything up and I put the intake back made sure everything was tight and looking good and filled it up with coolant and I still have the leak. What could this be?

 

Because every case is different and we can't be there to actually look, how about we suggest a thing or two?
Sometimes a mirror and flashlite can help to see where you can;t ordinarily see things.
If it is leaking with just gravity no need to use a radiator pressure tester unless it makes the leak area more noticeable..
Can we ask where did you obtain the replacement manifold and could there be a problem with it?

 

Check the heater hoses, I have a 2001, 5.4 with 345,000. Had a coolant leak in the rear of pass side, those quick connect fittings get brittle after a while. Mirror and flashlight at night!

 

Not sure if related but I have 2006 5.4 that had the T heater hose crack and leak as well. It filled up on manifold and could have looked like a leaking manifold as well. Cheap fix with replacement T from home depot plumbing department and a few hose clamps.