04 Expy 5.4L Overheating Need HELP

[Red97tib]

So here is a quick rundown. I am working on my neighbors '04 Expedition with a 5.4L 2 valve motor. Car came in and would randomly overheat, exhaust looked like a steam engine, and water would run out of the exhaust.

 

I assumed head gasket. I tore the hole thing down. I didn't see any cracks or marks in the block or heads to indicate an area of damage. The heads had a flatness of 0.0026" and 0.0023" overall max. I assumed that was within spec. I replaced all the gaskets with new and one of the timing tensonors. New plugs and checked all the coil packs. Replaced the fluids and restarted the thing. The exhaust looks like a fog machine still. The interior vents only blow cold so I assume plugged heater core or lines. (I didn't check that prior to the rebuild).

 

I let it run for a while but it still looks like a fog machine but I didn't let it overheat or give it a chance to. I let it idle for about 15 minutes. Water is obviously still running out of the exhaust.

 

So did I miss something here? Could the water jackets be plugged and causing a problem? Could I have a cracked block or heads?

 

I'm going to do a compression test when I get a chance but any ideas would be awesome.

 

Greg

[Red97tib]

So turned out that there was excessive water in the exhuast system. After running at idle for more than an hour this went away. O2 sensors were fouled due to the water but as the water left the exhuast the O2 readings became better. Car runs fine now.