did a pressure test ,it holds .
finnally got her running againe ,
did the head gasket ,intake gasket and it still overheats.
temp gos up to the red and after a few moments itr will go down,
when i pull over and check its seeping out of the res

fan does come on ,also installed new relay
the only thing i can think of is testing the switch,
would any one know the right precedure for testing a fan switch
thanks

fan will not come on when it heats up fast,
but when it comes on its too late ,and boiling over but temp gauge goes back down .

 

The switch should be linked with your A/C, if you have it. So, turning on your A/C should automatically trigger the fan, if I'm not mistaken.

I'm sure you probably covered these, but, just to cover the bases.

Have you checked to make sure the thermostat is working? Try checking/replacing it and see if you still overheat.

Have you verified that your water pump is working properly?

Have you checked timing? Timing can cause a car to overheat too.

Good Luck!