thermostat test

[dwaynos]

hi, does anyone know how to test a thermostat while it is out the car or is there no such way?

thanks

[Jeff in MN]

hi, does anyone know how to test a thermostat while it is out the car or is there no such way?

thanks

boiling water with a thermometer. If it is still functioning properly you will see the spring contract as the temperature rises and then go back closed on the cool down.
Good luck, it's easy.

[whiskychaser]

boiling water with a thermometer. If it is still functioning properly you will see the spring contract as the temperature rises and then go back closed on the cool down.
Good luck, it's easy.
x1
I would add that I have known them pass this test only to stick open a couple of weeks later. If in doubt I would put in a new one

[Dr. evil]

when mine when bad the car would start to run cold on the highway

[bsell]

do i put the whole thermostat in or just the bit which opens while i hold it

Don't be shy, throw the whole thing in the pot of water.

Does anyone know the initial opening temp and the full open temp for these things? A spec for this must exist somewhere...

I second the above recommendation to ditch a suspect thermostat as they don't cost all that much when compared to the time and trouble of swapping in a new one.

Brian

[Rick L]

x3
But also put in a thermometer and see if it opens right away at given temp of termostat.

[dwaynos]

do i put the whole thermostat in or just the bit which opens while i hold it

[whiskychaser]

Don't be shy, throw the whole thing in the pot of water.

Does anyone know the initial opening temp and the full open temp for these things? A spec for this must exist somewhere...

I second the above recommendation to ditch a suspect thermostat as they don't cost all that much when compared to the time and trouble of swapping in a new one.

Brian
Yes chuck it in a pan but dont let it sit on the bottom-suspend it with a bit of string from a stick across the top of the pan. IIRC mine is 80 deg C. Once they hit temp they open fully. As for spec, I bet nobody guarantees they will even open within a degree or two

[Ross]

Yes you can test it. water and thermometer in a pan of water, etc., etc.
Why bother with such an inexpensive part? If it is suspect or of unknown age just replace it.
There are certain items that once removed aren't worth diagnosing.