Just started hearing a ticking noise coming from the exhaust manifold (1999 Wrangler, 4.0 6cyl) after shutting down the engine. The ticking starts fast and gradually gets slower then stops after approximately 2 minutes. I stethoscope'd the manifold during the ticking and it is definitely coming from there. It has never done this before, so I am not sure what caused it. The was dry and outside temp was in the mid 50's. There is no audible ticking while the engine is running. It will do it whether the engine is hot or cold.
That's exactly what I thought, but it has never done it before, so of course I started expecting the worse. It has a newer (1yr old) upgraded manifold due to the stock one cracked, which is an issue with this year Jeep.