Hi Rob,

The valley pan is part of the cooling system in/around the intake manifold. Mine was replaced at 115K. The pan itself does not usually go bad, but the gaskets that seal around it do--you will have a coolant leak if this is the case. Have your mechanic do a pressure test of the cooling system and you can tell for sure.

If the gaskets need to be replaced, you might as well replace the engine vent hoses at the back of the engine at the same time since it's all part of the labor involved. The parts are cheap, but the labor will be a killer--at least 5-6 hours for a skilled mechanic.

Hope that helps!