Exhaust Check Valve?

[blue thunder]

I have a 66 that makes a rattle (not all of the time). There appears to be some sort of valve near the rear of the motor that opens or closes the exhaust?

It rattles at times and is rather loud. Any ideas? jim

 

[Joe Vandatta]

If it's the heat riser valve on the passenger side exhaust manifold it should have bimetal (temp. sensing) spring on it. Ck to see if it is in place.
Joe