Why we need themostat?
Imagine, if our car running without themostat, the water will flow as long as your engine started, perhaps you get better water temp for normal driving. Try going up genting, press all the way up, rev kau kau up, this time for sure your water temp will raise.
Themostat is to keep our engine at an optimum temp. by not too cold or too hot.
Too cold means themostat will block the water from flow to the radiator before certain temp.
Too hot means if the water flow without themostat, try imagine whats use of our radiator and fan? without themostat the water will not really cold down when passig thru the radiator. what i mean is that when themostat is close, water will stuck in radiator and our fan will blow on it to make is cold, once engine temp raise themostat will open and cold water will flow into our engine.
hope you guys get it and sorry for the bad gramma.