Take the air-cleaner off, open the TB butterfly valves and look down into the plenum with a flash light.
If you see "any" oil there, you have an intake oil plenum leak. It's about a four hour job for a 1st timer to replace the intake manifold gasket. Take your time and cover each step carefully. A good torque wrench is a friend for this job too.
INTAKE PLENUM GASKET REPLACEMENT
• V6, V8 - Manifold gasket leaks
o TSB 09-05-00 spark knock and excessive oil consumption
o V6, V8 Excessive oil consumption - intake manifold plate may be leaking, see note
• V8 5.2L '98 models:
o reports of oil leaks at the front timing case cover, oil pan, rear intake manifold gasket
Check out the link. This is the post with pics: http://www.dodgetalk.com/forums/showthread.php?t=59457