Originally Posted by shanks
just got my T-stat and am not sure if i should drill a hole ....is this really beneficial? and or is it recomended ... installed fwi today (couldn't get my tire off either , what a fun time it was ... think it was frozen on as it was -10*C outside ) anyhow I want to install my 180* t-stat tomorrow any olinks to the install process? Thanks
Without an air bleed hole, it is much more difficult to remove air from the engine when the cooling system is opened for repairs or maintenance. The highest point in the cooling system is the most likely place for trapped air to migrate. For the L36 engine, this high point comprises the coolant passages in the plastic upper intake manifold that, if not filled with air, will remove some of the heat from the EGR passage as they provide coolant for throttle body heat. Most thermostats used to come with a small air bleed check valve, and many still do. For several years GM eliminated the little valve. Who knows why? Perhaps they saved $.03 on every car they made and needed the money.
We have reports that when you buy a replacement thermostat at the dealer now, that it will come with an air bleed. There is no question that it is better to have an air bleed than not.
Buy a new rubber seal for the edge of the thermostat, and a new paper gasket for the thermostat housing/hose nipple surface if your car needs one. If applicable, clean any old gasket material from the sealing surfaces with a scraper. Keep debris from falling into the thermostat opening. If you fill your engine with coolant according to the procedure in Techinfo, you won't have any trapped air troubles. Coolant Fill Procedure