79 Buick Estate Wagon, 148,000 mile, 403 engine. Noticing an increased exhaust noise in engine bay, can't tell exactly where it's coming from. Hopefully just at the manifold tailpipe connections. Will be taking to a shop but would like to know a bit more than I do such as are there gaskets (donut type or other) at the manifold tailpipe connections?

 

Yes on the passenger side rear outlet. Oldsmobile V8's didn't use exhaust manifold gaskets. I seen a few leak working in a garage. We installed a gasket and we never had any return.

 

Thanks! Since the manifold ends are already shaped conically to fit into the tailpipe, are we talking about a flat fiber type gasket or ? Do you recall what size?

 

They were usually blue fiber with a metal ring built into the top. It is basically the shape of the metal cone built into the manifolds on the crossover pipes. Carefully tighten the three bolts by hand and don't go too tight.

 

have had good luck with RemFlex gaskets I cleaned up head and exhaust manifold surfaces as best I could while still attached to the exhaust pipes on the car. I used a flat file covered with 220 grit sandpiper then cleaned it off with brake cleaner and a paper towel. Remflex can deal with a lot of warpage.. 20lbs torque at most..

 

something like this