Jeep 1996 Grand Cherokee Service Manual - page 1017
CYLINDER BLOCK
CLEANING
Clean cylinder block thoroughly and check all core
hole plugs for evidence of leaking.
INSPECTION
Examine block for cracks or fractures.
The cylinder walls should be checked for out-of-
round and taper with Cylinder Bore Indicator Tool
C-119. The cylinder block should be bored and honed
with new pistons and rings fitted if:
• The cylinder bores show more than 0.127 mm
(0.005 in.) out-of-round.
• The cylinder bores show a taper of more than
0.254 mm (0.010 in.).
• The cylinder walls are badly scuffed or scored.
Boring and honing operation should be closely coor-
dinated with the fitting of pistons and rings, so that
specified clearances can be maintained.
OIL LINE PLUG
The oil line plug is located in the vertical passage
at the rear of the block between the oil-to-filter and
oil-from-filter passages (Fig. 68). Improper installa-
tion or plug missing could cause erratic, low, or no oil
pressure.
The oil plug must come out the bottom. Use flat
dowel, down the oil pressure sending unit hole from
the top, to remove oil plug.
(1) Remove oil pressure sending unit from back of
block.
(2) Insert a 3.175 mm (1/8 in.) finish wire, or
equivalent, into passage.
(3) Plug should be 190.0 to 195.2 mm (7-1/2 to
7-11/16 in.) from machined surface of block (Fig. 68).
If plug is too high, use a suitable flat dowel to posi-
tion properly.
(4) If plug is too low, remove oil pan and No. 4
main bearing cap. Use suitable flat dowel to position
properly. Coat outside diameter of plug with Mopar
Stud and Bearing Mount Adhesive, or equivalent.
Plug should be 54.0 to 57.7 mm (2-1/8 to 2-5/16 in.)
from bottom of the block.
Fig. 67 Proper Installation of Retainer Cap
Fig. 68 Oil Line Plug
9 - 80
5.2L ENGINE
ZJ
CLEANING AND INSPECTION (Continued)