testing a new thermostats opening temp 2002 2.5L V6

[cc]

Guys
Before putting it in I want to test it for correct operation.
Just immersed the new thermostat in 100 deg C and it didnt open, nor did the old one.
Anyone know at what temperature they open? Reading posts give the 90 deg everyone is familiar with for the the running temp of the engine. Im after the temp it opens at.. Was going to bake it in the oven at 110 deg.

The old one when cold was buggered as it was about 3mm open.
They opened in the oven at approx 95 deg. Still wondering if the new one should be slightly open when cold...

[johnl]

I'd be surprised if a new thermostat didn't work properly (at least I've never bought a faulty one), but it can't be ruled out. How long did you expose the thermostat to heat? They do take some time to open, it's not 'instant'. Assuming it will open further as it gets hotter, a thermostat that is even a little open at room temperature is definitely a problem. The engine will take a long time to heat up, but may well be fine once it does. Or, it might be stuck and cause the engine to take a long time to heat up, but then to overheat.

A "90°" thermostat should start to open before the rated 90°. My understanding is that thermostats should be half way open at the rated temperature, I don't know what that temperature might be (nor what it might be at fully open). When testing thermostats I immerse them in warm water in a pot on the stove and then turn on the heat. Typically I start to see them slowly start to open at about the same time I start to see small bubbles forming on the bottom of the pan. They are usually fully open before the water starts to boil properly.

I have a suspicion that the thermostat fitted in the 147 TS engine may tend to start opening at a relatively low temperature, which (if true) might explain why the engine seems to take more time than most others to reach full temperature. At least this is what I find with my car, which has had a new thermostat fitted relatively recently because when I bought it the only time the engine would come to full temperature was in slow traffic, on the open road it would drop down well below the 'normal' indication. Fitted a new one (fully closed at room temperature) and the temperature is now stable, but it still takes what I consider (compared to other cars) to be an excessively long time to reach full temperature (as indicated on the gauge, which is less than a precise indication of the actual temperature since it will - as I understand its function - indicate a steady 'normal' for maybe ten degrees or so each side of the 'ideal' temperature?).

At some stage I'd like to fit a 'real' temperature gauge, along with one for the oil pressure.

Regards,
John.