Thermostat movement

[bromy]

Started having slight overheating lastnight so I have ordered a new rad cap and thermostat from toyota today. Symptoms have been rising temperatures, no hot air in the cabin, top hose hot and bottom hose not so warm.

 

I am thinking along the lines of circulation i.e thermostat stuck closed. Tonight I took the thermostat out ready to put a new one in next week and thought I would test it in a pan of boiling water but to my dismay it opens. How much should they actually open? I measured around 9mm fully open. Would this be enough of a restriction to cause overheating? Or should I be looking at the water pump?

[Homer]

I think that's about all they can open, however it's the tempurature that makes the difference. It should open fully after 82degrees, not in fully boiling water.

 

I did a test on my old one after a similar problem, placed the old stat and a new one in a pan of water and broughto 90 degrees, the old one was only open a couple of mm, the new one about 8-9mm. With the water on full boil they were both fully open.

[bromy]

I think that's about all they can open, however it's the tempurature that makes the difference. It should open fully after 82degrees, not in fully boiling water.

 

I did a test on my old one after a similar problem, placed the old stat and a new one in a pan of water and broughto 90 degrees, the old one was only open a couple of mm, the new one about 8-9mm. With the water on full boil they were both fully open.

 

Ahhh good point on the temperature. I dont have a thermometer so I cant tell what temp the water is at, I will just have to bang the new one in next week.