Okay, all good input.
Let's see . . . yes, it's a low cost option (oops, no cost really . . .) to check the fluid levels - and we know the fluids are all solid.
I'm not going to even address the confluence of this "problem" coinciding with the seasonal change in the ethanol ratio mix in the local fuel supply - as there simply cannot
be a connection between the engine fuel supply and the cooling system. This is apparently just a fun-loving extension of the correlation without causation argument (sort of like firemen can always be found to be present at fires, therefore firemen cause fires). Grade = F -
From having experienced a failed thermostat twice, I think I know what that looks like. It looks like an overheated engine when water doesn't pass from the water jacket, and back through to the radiator to be cooled. I remember my dad's advice that when the thermostat fails in the closed position, you can sometimes mitigate the overheating of the engine, by running the heater at the highest fan speed, as the heater core will actually act as an auxiliary radiator, on the engine side of the coolant loop (that was a neat tip, thanks dad - although it's not too much fun on a hot summer evening . . .).
Not sure about the origin of the speculation about a "missing thermostat", since how does the thermostat "get out" of the coolant loop (?) - and kidnapping a thermostat for ransom, seems like science fiction. All of that light-handed
rhetoric aside, talking this through (more exactly, typing it through
), is helpful, because I was trying to "visualize" what [harm] happens when the thermostat fails in the open
position. As I thought through it - what happens may be exactly
[the symptoms] we're seeing though. In that situation, the water pump circulates water almost continuously through the water jacket, and the water never
really stays in the water jacket long enough to get up to a temperature that allows heat to transfer from the heater core (or to be registered on the temperature gauge). I never thought why the thermostat is really necessary, but it's actually there to make sure the water does
get up to a certain temperature. I think the low-cost first step solution is to replace the thermostat - and see what happens (since it's probably the original thermostat from when the vehicle rolled out of the factory . . .).