I'm aware of the 2.7 problems, and I'm a fairly good mechanic - but I'm stumped.

Engine was overheating, but heater wasn't warming up. I replaced the thermostat (twice in 200 miles). Then I replaced a perfectly good water pump, and installed the timing chain kit. Engine runs great.

There is no coolant in the crankcase, and no oil in coolant. Cylinder compression is good, and holds. I bled off the air in the coolant system while refilling.

After about 7 minutes at idle, the temp gauge doesn't move (sender if fine). No Heat, water pump intake is warm, the heater tube at thermostat housing (which bypasses the thermostat) doesn't seem to have any flow, it doesn't warm up at the junction near the back of the drivers side head and firewall. - it bypasses the thermostat.

It still seems like there's air in the system, the W-pump doesn't seem to be circulating the coolant.

Any ideas?