Dodge 2000 DURANGO Service Manual page 298

8D - 12 IGNITION SYSTEM
REMOVAL AND INSTALLATION (Continued)
(3) Remove spark plug from cylinder head using a
quality socket with a rubber or foam insert. If
equipped with a 4.7L V-8 engine, also check condition
of coil o-ring and replace as necessary.
(4) Except 4.7L: Always remove spark plug or igni-
tion coil cables by grasping at the cable boot (Fig.
20). Turn the cable boot 1/2 turn and pull straight
back in a steady motion. Never pull directly on the
cable. Internal damage to cable will result.
(5) Inspect spark plug condition. Refer to Spark
Plug Conditions.
CLEANING
The plugs may be cleaned using commercially
available spark plug cleaning equipment. After clean-
ing, file the center electrode flat with a small point
file or jewelers file before adjusting gap.
CAUTION: Never use a motorized wire wheel brush
to clean the spark plugs. Metallic deposits will
remain on the spark plug insulator and will cause
plug misfire.
GAP ADJUSTMENT
Check the spark plug gap with a gap gauge tool. If
the gap is not correct, adjust it by bending the
ground electrode (Fig. 23). Never attempt to adjust
the gap by bending the center electrode.
Fig. 23 Setting Spark Plug Gap—Typical
1 – GAUGE
2 – SPARK PLUG
INSTALLATION
CAUTION: The 4.7L V–8 engine is equipped with
copper core ground electrode spark plugs. They
must be replaced with the same type/number spark
plug as the original. If another spark plug is substi-
tuted, pre-ignition will result.
Special care should be taken when installing spark
plugs into the cylinder head spark plug wells. Be
sure the plugs do not drop into the plug wells as elec-
trodes can be damaged.
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion resulting in a
change in the spark plug gap or a cracked porcelain
insulator.
Except 4.7L Engine: When replacing the spark
plug and ignition coil cables, route the cables cor-
rectly and secure them in the appropriate retainers.
Failure to route the cables properly can cause the
radio to reproduce ignition noise. It could cause cross
ignition of the spark plugs or short circuit the cables
to ground.
(1) Start the spark plug into the cylinder head by
hand to avoid cross threading.
(2) Except 4.7L Engine: Tighten spark plugs to
35-41 N·m (26-30 ft. lbs.) torque.
(3) Except 4.7L Engine: Install spark plug cables
over spark plugs.
(4) 4.7L V–8 Engine: Tighten spark plugs to 27
N·m (20 ft. lbs.) torque.
(5) 4.7L V–8 Engine: Before installing coil(s),
check condition of coil o-ring and replace as neces-
sary. To aid in coil installation, apply silicone to coil
o-ring.
(6) 4.7L V–8 Engine: Install ignition coil(s). Refer
to Ignition Coil Removal/Installation.
IGNITION COIL—3.9/5.2/5.9L ENGINES
The ignition coil is an epoxy filled type. If the coil
is replaced, it must be replaced with the same type.
REMOVAL
The coil is mounted to a bracket that is bolted to
the front of the right engine cylinder head (Fig. 24).
This bracket is mounted on top of the automatic belt
tensioner bracket using common bolts.
(1) Disconnect the primary wiring from the igni-
tion coil.
(2) Disconnect the secondary spark plug cable from
the ignition coil.
DN