3.0 Low Idle
Just recently, I noticed something after a drive. While sitting there idling, fully warmed, the engine will slow rotation down to about 600RPM and idle somewhat rough. It doesn't feel like it's going to stall, and is very steady.
However, if the idle is raised just slightly, the roughness instantly goes away. There are no other symptoms. This makes me consider it's a vacuum leak, but there is no check engine light and I don't hear the iconic hissing sound of a vacuum leak.
Is this normal? 1999 Flex Fuel 3.0 automatic, 114,5xx on the clock.