Struggling to bleed 20XE cooling system

[Iain]

Just fitted a new thermostat, stat housing and radiator and struggling to get things working properly

Engine will get so hot it's almost on the red on the Nova dials (anyone know how hot this really is?) and if you turn it off the coolant starts to boil

Fan doesn't kick in either (but it does if you bridge the sensor wires in the rad)

Any suggestions on what to do? As far as I know the rad sensor is working as expected as it's not that old.

Cheers!

[Benn]

Is the stat opening? Rad getting hot?

Doesn't sound like the fan switch is working.

[Iain]

Yeah rad is getting hot and top and bottom hoses pressurise somewhat when it gets very hot

Got an old rad sensor to try so will report back

[Iain]

Well there you go I'm such an amateur lol Million year old GM rad fan works and shiny new looking motor factors crap doesn't lol Fan kicks in just under half way on the temp :)

[Benn]

Just there it should.

[chrisnovaturbo]

put the fan switch in a cup of hot water and cheack with a multi meter to see if it works. it should work at 98 deg. also leave header tank cap off take the top rad hose off the header tank put your thum over the hose to block it up than squeeze the bottom rad hose in and out that should get all the air out.

[chrisnovaturbo]

im a bit late now if you sorted it lol

[Iain]

I heard it was 102 degrees?

I actually put this new switch into some freshly boiled water and it didn't show the results I expected (continuity between the pins) but it works fine in the rad.

Edit: Yes late but thanks anyway! :)