have been reports of loose intake bolts on some of the 90's 4.0L's.
Check - Check for
loose lower intake manifold
bolts. Pull your #5 plug and check it out. If you see the
fuzzy head or have some oil present around the sides of the plug then
bingo. The 93-94 have this problem VERY often. Usually you can
fix it by simply tightening the bolts (in the PROPER sequence), but
sometimes you need a new gasket. Do you notice a loss of oil with no
leaks? Say 1-quart every 1500-3000 miles?
is a simple fix...you will need the following:
the pictures below for the location and proper tightening sequence. Most
should be able to solve the problem by simple tightening, but some may
need to replace the entire gasket as it may be shot. Make sure you follow
the sequence for tightening!