I picked up a 1999 E250 with the 5.4L and 157K from its first owner in January. She's been great until earlier today. On a quick run to the store, she started blowing white smoke, coolant tank was dry, oil cap all milky. That spells only one thing to me, but Id love to hear thoughts from folks with more experience with these engines.

I've driven her perhaps 1200 miles since owning her with no running or idling issues, minus a couple very short stutters that I presumed to be just some gunk in the lines finding its way through. Temp gauge has been rock solid at about 1/3, and remains to be. It hasn't gone up a hair with these new developments, although I've only put on maybe 5 miles to get her back home and a bit of idling while the scanner did its thing. (P1151 and P1152 stored codes for oxygen sensor, nothing else.)

The only things that stick out to me from the past few months was an initially low coolant level (not drastically so - like a slightly leaking hose connection amount) and cabin heat that wasn't as warm as it should be. No external leaks that I've seen.

Obviously she needs a compression check at the very least, but I thought I'd throw this out to you folks while I'm waiting to get to it. I'm decent with hacking my way through my own repairs but I'm very slow and currently don't have the available time or space to tackle something quite that involved. Cursory research into the cost of a head gasket replacement has me looking an engine swap as a possible option should this ultimately be the bad news.

I'd love to hear what you folks have to say if you have a minute. I'll start my forum search for engine swap details before asking too much on that. Plus, I'd rather not get too ahead of myself ...

 

Think positive !
It could only be an intake manifold problem. Suggest pulling some plugs and try to pin down which cyl(s) might be involved. You should be able to see the difference on the affected plug(s). If the engine was fairly well maintained you would have to pull the intake anyway to do any engine work.
If a head gasket was the problem, I would think an overheat condition would be present. Let us know what you find, thanks.