It's probably been posted before, and I usually do this but it was brought up again last night when I checked the new thermostat for my race engine. I bought a 180 deg thermostat and it was supposed to be the "good" one. Well I checked it with both a candy thermoeter, and the aftermarket gauge that I am going to use (I wanted to check the accuracy of the gauge at the same time) well this 180 deg thermostat didn't even start to open until almost 200 degrees, and didn't go fully open until 215 which is way too hot for my application as I have enough trouble keeping this thing cool as it is so back to the store I go, but just thought I would remind people maybe checking all thermostats before you install them in your car even a stock engine is a good idea, just imagine if that had been a 195 deg that was off by that much which would make the beginning to open temp 215 and fully open at 230 kinda overheating things just a little
BTW this isn't the first time I have had one that was off, and actually wasn't the worst I have seen, I once had a 165 deg brand new that at full boil 230+ it never did start to open and it was brand new. And I also have been known to go through as many as 8 before I find one that is close enough to use. And guess what when I take them back do you think they return them to the manufactor for defect? Nope they just put them back on the shelf, and sell them to the next poor sap that comes along who doesn't check them.

 

That is very good advice for anyone replacing a stat.

 

How did you get boiling water above 212F?????? I'm assuming you were using water?

 

actually the one that I mentioned there when I couldn't get it to open at full boil I swtched and used cooking oil to see at what temp it would open.

 

That's good!!

 

That's why I always say: New means new, it doesn't mean good.

You might get better results if you exercise the stat a few times before testing. I have had new ones that wouldn't open at all until you worked them a little.