Thermostat housing size

[cthudak]

Hi guys,
I need to replace my thermostat housing pipe, and rock auto offers a 35 and 40 mm size. I measured the diameter of my housing and doing the math it seems mine is neither, falls right between the two. Is there a quick way to know which fits my 97 4.0 ohv? Also is a 195 degree thermostat ok? Live in Seattle , rarely gets below 20 in winter.

Thanks for all the help

 

[RonD]

Yes, on the 195degF t-stat, t-stat sets minimum operating temp, has nothing to do with outside temp.
A lower temp t-stat, in this engine, will decrease MPG and not clean the oil as well.

In 1997 Ford came out with the 4.0l SOHC engine in the Explorer, Rangers got it in '01.
Your '97 Ranger has a 4.0l OHV engine, as you said.
Not sure why there would be two different sizes, for the 4.0l OHV engine

 

[cthudak]

Thanks for the reply,
Not sure either about the 2 diameters. Motorcraft makes the 35mm but 4 seasons makes both the 40 and 35mm. Guess I have to buy both and return the other