• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Thermostat

Share this page

Anthony_S

Anthony_S

Senior Member
Offline
Hello, Is there a specific way to tell if the thermostat on my TR3A is going out or is bad. Im pretty sure it is still functioning but part of me thinks not to its full potential. Driving it this last fall it seemed to get warmer than it should and when I tapped on the thermostat housing it would seem to cool down a bit. Maybe I am imaging all this but was curious what ya'll think.

Thanks
Anthony!
 
Pull it out and stick it in some water on the stove with a thermometer in it.
Turn the stove on and watch.

Another way is get an IR temp reader and point it at the housing.
Tap it and see if the temp changes

These are just guesses
 
Just replace it..theres a couple of differant kinds..summer or winter..after that if you still heat up you got other problems.
 
DNK said:
Another way is get an IR temp reader and point it at the housing.
Tap it and see if the temp changes
Click to expand...

With my IR thermometer, you can get a 20 degree or more variation, just by slightly changing the exact point you "shoot" on the housing. The emissivity of old aluminum varies all over the place (and is nowhere near the value assumed by the thermometer).
https://www.engineeringtoolbox.com/emissivity-coefficients-d_447.html
 
If it is an original style bellows thermostat, the way you tell they've gone bad is your engine temperature pegs. They fail in the closed position when the bellows loses its seal. I was very lucky to catch that condition in time before it became a real issue for me.
 
Back
Top