whyndman

I pulled the motor on my 1980 Corvette and both EGR valves cracked. Are these the same valves and does anyone have the part numbers? One screws into the thermostat housing and one directly into the intake manifold.




Thanks for your help. Bill

Easy Mike

Those are thermal vacuum switches (TVS), not EGR valves. I believe both are still available from the aftermarket providers.

Bikespace

They are tied into the EGR system (and others) to control thermal vacuum events. You don't need them if you bypass most of the emissions and cold weather start equipment. You can then run a gooseneck without fittings.

If you need them for emissions, Willcox has a good vacuum diagram.

whyndman

It looks like there are 3 thermal vacuum switches on my intake manifold (pictured). 2 screw into the thermostat housing and another one directly into the intake manifold. Are 2 of them the same parts? The 3rd one is easy to identify because there are 3 connections on it. Thanks.