btw, I've pulled the thermostat and checked it in boiling water, it opens and closes fine. I've disconnected the heater core hoses and flushed them out. I did a compression check and 1, 3, and 4 were at 200 psi after 7 good cranks while number 2 was at 188. While that one is lower than the others, it is not enough to convince me there is a problem with that particular one.......yet.
I did a combustion leak check (blue dye) and have only been able to get it to turn pale green/yellow once out of about 5 times.
It still overheats, but not badly, within about 5 miles. The wierd thing is that the gage will climb, then fall back down, rise again, fall back again. If I get back home and it's up, then by the time I get the hood open and slowly release the cap (to do a combustion leak test while it's "hot") the temp has come back down again.
I'm pretty sure it's a blown head gasket, but it must be a small one that only blows well under a good head of pressure (load). I just want to make damn sure before I tell my Mother to spend $1500 or think about getting rid of it.
Is there ANY way trapped air (in the head) can be doing this?