One my 97 5.2 I looked down the throttle body and could that the bottom of the plenum was wet with oil. Installed a set of Felpro gaskets and has been good since.
72 Satellite Sebring Plus 440, 72 Dart 5.9 4-spd, 68 Valiant, 73 W200, 78 D100 sb, 78 D200, 98 DAKOTA, . Moparmarks Parts & Restorations Desert Mopar Metal Grand Jct. CO 970-261-7039 http://moparmark.com/ motormangj@gmail.com