Testing a Thermostat, running cool?

[ChrisC]

OK silly question

 

I have done the old thermostat in boiling water test, it opened no problem, but closed when I felt the water was to cold. So could I have a lazy stat?

 

The stat is marked 82 - 97, so I assumed it would open at 82 and be fully open at 97. It actually closed at about 65, which is where my car is running normally, matching up with the gauge (Caterham original). I suspect all is ok with my cooling system, gauge and sensor, because the ECU uses the same sensor, and switches on the Fan when the gauge reaches 110 ish in traffic.

 

So is it possible to have a lazy stat?

[Stationary M25 Traveller]

Do you mean thermostat or fan switch ?

[ChrisC]

Thermostat is what I think is being lazy, staying open at 65c (and not the 82 mark on that stat)

 

I think the sensor and gauge (recently replaced for other reasons) looks fine, when compared to my measurements using my IR thermometer.

 

Should have said its a Sigma, so it only has one sensor for the ECU and gauge, the ECU controls the Fan. I don't have any overheating issues, just cool running.

 

Edited by - ChrisC on 20 May 2014 16:15:52

[diggerman]

The stat should close at 82deg. If not, its bu££ered and should be replaced otherwise you will be suffering over-cooling which results in excessive wear , condensation, sludge and general 🙆🏻's.

 

A stat is cheap and a new one will keep your engine nice and cosy.

 

Peter