86 supra problems

[drs77]

I had a 22RE, albeit not a Supra engine, that did the same thing, got super hot, blew cold air from the heather. Kept putting off a HG, cracked the head. That's one of the reasons I now have 5MGE in my 4R (although not running right). All I can say is change that head gasket ASAP, if not you'll more than likely crack your head, you can only top it off so much. The oil sounds like valve cover gaskets. In working on my engine, thsese MGE series seems to be pretty easy to work on and understand. There's a copy of the TSRM floating around here somewhere, that'll tell you what you need to know to get it gone. From my experience the oil gage moving up up and down with the RPM is normal, the oil pump is driven off the timing belt, the faster it moves, the more oil is pumping, the more pressure you get.
Dyl