When the exhaust manifold gasket becomes corroded to the point of failure, it no longer muffles engine exhaust noise, and the result will be a tapping noise from the exhaust manifold. If the muffler bracket has broken, or the rubber hanger is worn, the muffler and exhaust pipe may hang down, placing additional strain on the hot manifold, and cause the exhaust manifold gasket to leak. Lastly, the manifold gasket leaking could register as lean fuel conditions at the oxygen sensors, causing black smoke from the exhaust under heavy acceleration, check engine light illumination, and OBD trouble codes for exhaust and emissions, fuel delivery, and lean running conditions.
More exhaust manifold gasket symptoms
