Right exhaust manifold valve?? - Third Generation F-Body Message Boards

sa85z · 05-29-2002, 05:22 PM

Removed all the AIR stuff today but came across a valve of sorts at the junction of the exhaust manifold and the y pipe. It appears that this valve is vacuum controlled as it has a very small. hard plastic vacuum line that runs to a junction on the thermostat housing. From there another line runs to the AIR control valve. What do I do about this line / exhaust valve? Right now I left it in place to the junction and plugged the side that went to the now departed AIR control valve. Any input would be appreciated.

Vader · 05-29-2002, 06:54 PM

85,

That is a heat riser valve. If it is the vacuum actuated type as you describe, it has a return spring that defaults the valve to the OPEN position. This is so that when (not IF) the vacuum line or actuator fails the valve will remain open and not become an obstruction to exhaust flow. You should be able to abandon the valve in place without creating a restriction.