more than likely your valve covers are leaking and that's why theres oil down in by your spark plugs
tighten up the valve covers
check your oil cap for chocolate milkshake looking stuff
sounds like you have a water flow problem....
replace your thermostat with a new one
if that don't work then maybe your radiator is clogged and not circulating water properly
you don't hear noises from the dash so that would suggest that you don't have air bubbles in the system
i would personally do the thermostat
http://www.cygnusx1.net/supra/librar.../co/CO_08.html