Hello all,
As a preventative maintenance I replaced the t.stat. (Every year in any car before summer) since then, my temp is changing oddly.
Before it has never passed the 1/2 mark no matter what. Now its climbing to 3/4and down and again or stay at the 3/4 , Hwy or in own(No over heat or a/c yet)this is the 2nd t.stat (replace by a mechanic) and it is low temp.
Both fan are working properly.
Car has no leaks, no water in oil, and no loss of power.
2k ago w.pump, t.belt.
Oil change every 3k miles (valvolin semi sync)
8k ago radiator, full tune up
Car has 128k on andis a commuter of 400 miles a week.
Any ideas?
thank you
ron

 

Did you bleed the air out of the system when you refilled the coolant?

There is a 10 or 12mm valve on top of the thermostat housing that you unscrew to release any air trapped in the system. Do this with the radiator cap off. The air will spit out of there and you will eventually get a steady stream of coolant coming out. Close that valve and top off the radiator.

 

I didn’t do the t.stat change due to lack of time.
I assume that the mechanic did it.
But, isn’t air in the system will result in over heating?
thanks,
ron

 

The temp. sensor will misread the real temperature when there is air in there. It is something that takes a couple of minutes and is simple to do. Your mechanic might have simply forgot to bleed the air out of there.