Thanks for the question ..Goatman. Maybe you could shed some light.

I have made another post about this, just for info.

What the 940 is doing, and has been doing for a spell ..is as follows.

1) I fill the cooling system up to mid level in the reservoir, squeezing and pushing hoses and all till you are pretty sure there is no air pocket in there.

2) Invariably it will pull all the coolant down into the block after it gets hot, not showing any if much in the reservoir.

3) Till yesterday the needle was staying mid point on the gauge, and at times the electric fan would run a long time (3-5 minutes) at shutdown, but not every time.

4) Yesterday the wife was driving it home and the temp needle was moving from nearly in the red to almost back to mid range. She knows to turn the heat on, but there was no real heat coming out. When she got home - the lower heater hose was hot - the upper not - indicating low coolant.

Quick history...
All my problems started when I had to replace a busted radiator a few years back, due to an accident. Lost all coolant - got real hot, but not to the point of rattling the valves. From that point on it was a struggle to keep the cooling system constant.
Months back bottom hose by the oil filter burst, losing all coolant again. Wife thinks she cut it off quick enough, but I am not 100% sure.
Within the last 2 months, car was losing pressure and coolant was leaking somewhere. Had a bad heater hose and valve. Ordered parts + a new cap from Groton and replaced.
The only other thing I have replaced in all relation to this was the t-stat, which did not have the vent hole. I made one with a drill to compensate.

Ideas? Anyone chime in here with Goatman if I am off track in pulling the head.

Thanks.
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' Of all bad men religious bad men are the worst. '' (C S Lewis