how do i replace a thermostat housing? on 1995 Chevrolet Lumina

i have a persistent leak from somewhere around my thermostat housing.what am i missing in my troubleshooting?

Asked by for the 1995 Chevrolet Lumina
you could get some dye and add to the cooling system and let it run and watch where the dye or leak is coming from. it will turn floresent green in color.

1 more answer
Some of the 3.1 liter engines leak coolant from their Intake Manifold Gaskets, be sure to check for that. Also do a pressure test of the whole system to see all the places where it may leak.