Internal Thermostat Testing

[echrisconnor]

Last season my car was running hot. The engine is currently in pieces as I'm rebuilding it, but while out, I thought I'd see if I could find any contributors.

This morning I pulled the internal thermostat out and dropped it in a pan of boiling water to see if it would open. The test seemed to work, and the thermostat opened about half way. Is this enough though? At boiling temperature (212F-ish), should it be open more than that?

Below is a picture from a previous thread on this topic. Mine looks about the same as the one on the left.


So, is half-way far enough, or should a properly functioning intnernal thermostat open more at this temperature?

[rcwaldo]

I had done the same test while I was rebuilding a 2.7. I found the original thermostat was not opening much to my surprise. I ended up buying a used one that worked. While testing that one in boiling water, I found it only opened about what I see in your picture, IIRC...

Chris

[echrisconnor]

So, half way is about as far as could be expected for this to open at boiling temperature? Has anyone boiled a new one to see if they get the same results?

[banjomike]

I thought it was supposed to open at 180deg F, so by 212 it should be all the way open.

Maybe Chuck from Elephant racing will chime in.

[echrisconnor]

Yes, if Chuck chimed in, that'd be great. My assumption is that like any thermostatic spring, it moves gradually and incrementally with heat. It probably begins to open at 180, but may not be fully open until 220-- beyond what I can boil to. So, if someone knowledgable said "that's as far as it goes when boiled." I'd believe 'em, but am still uncertain as to whether half way is what a new one would open to at this temperature.

[1980 911 sc]

hmmm how about using cooking oil and a thermometer and test your own theory?

[Fishcop]

DON'T use a propane torch for the test....

I did, and I'll say no further on the matter

[Early_S_Man]

Cooking oil and sauce pan never to be used with food again ... monitored with thermocouple probe and digital thermometer or multimeter with temp function would be my choice for the test!

Real important not to choose one of the wife's favorite pans!!!

[oneblueyedog]

I boiled a new one after I found my original wouldn't open. It opened like the posted picture.

Lee78Sc

[echrisconnor]

Blueye - so are you confirming this? A new thermostat will open about half way, like the one pictured. So, if my old one opens like this, chances are, it is functioning just like a new one.

Thanks.

I'm not going to venture down the "Boil it in oil!" path. My wife would already be quite nonplussed if she knew I'd boiled this one using one of her pots.

[echrisconnor]

Blueye - so are you confirming this? A new thermostat will open about half way, like the one pictured. So, if my old one opens like this, chances are, it is functioning just like a new one.

Thanks.

I'm not going to venture down the "Boil it in oil!" path. My wife would already be quite nonplussed if she knew I'd boiled this one using one of her pots.