Fluctuating Radiator Fluid

[trvlngnrs]

My 8v92 was cold yesterday, and I noticed the radiator fluid level was
half way up the sight glass. I had just recently filled it.

I drove about for 20 minutes, and the sight glass was empty. There is
no water in the trans fluid or oil. No noticable leaks.

This morning it was still empty. I turned the block heater on, to
preheat it, and about 2-3 hours later the sight glass was full of
green fluid.

I drove it back to the storage yard, and it was still full.

Any idea what is going on? I thought that it was empty because the
thermostat had opened and drained the fluid into the engine, but I
don't understand why it would raise back up with the block heater on.

Should I top it off again?

Steve Harrie
St. George, UT
'86 PT38 Leaving for Quartzsite Monday.