Sorry for what ur having.having ur temp rising and droping is not an indication of hg blown,u have a problem in the weater circulation,start by flushing ur radiator coz a blocked radiator will overheat the engine on steep hills.morning time b4 u start the beast open the cap of the water tank,start it up and see if the water is returning to it,if no water returning it means:
1.blocked hose or hoses
2.water pump failure (not circulating the water)
close ur cap after checking the flow of water,keep ur engine running at idle,wait 4 20 min aprox,then touch the bottom hose of the rad if it is cold it means that the thermostat is seized in the closed position thus not allowing the water 2 circulate in the rad for additional cooling.
a hard rad top hose means pressure is build in the system (it can get hard also even if ur hg isn't blown=water pump) blocked water circulation.
do u have oil in the coolant?do u have coolant in the oil?white stuff like mayonaise on the oil stick or under the engine oil cap?these r signs of bhg.
if high milage in done in ur car:
replace ur rad
replace viscous fan
replace hoses
replace thermostat
replace expansion tank cap
replace water pump
these are the first things to start with b4 changing the hg,or checking for slipped liners.
![Big Grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
:doh:
good luck