overheating st Options

[Malhar95]

i recently noticed, that my gauge reads hot sometimes and then drops quickly, first time it did that i checked the coolant, was a little low added water,

and then it does it randomly, coolants level is good. however when i turn the blower on (with temp to hot and AC button on) the needle comes down.


i also noticed the first day, that its leaking from where the bottom radiator hose connects to the engine, above the transmission area.
but yesterday when i was filling up gas, (it wasnt over heating or anything, i just checked) i saw its not leaking from there, but its quit wet under the coolant reservior and it was bubbling.

im guessing its the thermostat, but any input from you guys? how do i diagnose a thermostat, other than taking it out and puting it in a hot pan?

[rm240sx]

Ok you know your car is overheating due to coolant boiling out of the reservoir. so its not a faulty sensor. The reason it goes cooler when you turn the heat on is because its acting as a mini radiator under your dash. there is something stopping your coolant from flowing through the engine. If your fans are coming on those are good. The things it could be are the radiator is blocked, hoses blocked or weak and collapsing, Bad thermostat not opening to let coolant flow, or water pump not circulating coolant good enough. theres really not much to a cooling system.