toyota surf v6 not getting hot

[dan-n]

i have replaced the thermostat and the temprature gauge stays on cold. then when it has been sitting for about 5min the temp gauge is half way (were it shuld be) then as i drive it goes back to cold. any ideas on what it could be?

cheers Dan

[floatingkiwi]

Jiggle pin at the top of the thermostat? Air lock?

[nzlux]

new thermostat jammed open?

[zukmeista]

new thermostat jammed open?

To check boil it in a pot of water see if/when it opens.

[dan-n]

it seems to have fixed its self i was driving it for about 10ks then the temp shot up to half way. the new thermostat must have been jammed. thanks for your help

[tallsam66]

I assume you installed the jiggle valve to the top ( if it has 1)

[tweake]

more than likely air locked. especially if heater(s) where not open.
check the water level again.

[dan-n]

By saying giggle valve facing up you mean facing away from the motor? I jacked the front up and had the heater on with radiator cap off until heater got hot. Seems to be working now so i will just keep checking the level for afew weeks and go for a few drives before going too far in it.

[tweake]

i'm not sure where the thermostat sits in those motors but giggle pin needs to sit where the air bubble would sit.

[ChurchurDan]

Way back when I was an apprentice I was told by an older mechanic to cut the jiggle valve off and just leave the small hole open as it makes it a little bit easier to bleed the air out.

[tweake]

Way back when I was an apprentice I was told by an older mechanic to cut the jiggle valve off and just leave the small hole open as it makes it a little bit easier to bleed the air out.

thats quite bad.
removing the jiggle valve stops the air getting out.
it works something along the lines of the waters surface tension stops the air going through the small hole. the jiggle valve is there so its movement disrupts the surface tension.