Spark Plugs; Checking And Changing Spark Plugs - Volvo 5.0OSiE-J Operator's Manual

Maintenance
CAUTION! To prevent possible injury caused
by someone inadvertently starting the en-
gine, remove the ignition keys from each
starting location (especially if the engine
room/engine compartment cannot be seen
from various remote starting positions such
as a flybridge or enclosed cabin).
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Spark Plugs

Before installing new spark plugs, always check for
1
proper type and gap . Incorrect spark plugs can cause
operational problems and possible internal engine
damage.
Before installing a spark plug, the spark plug seat in
the cylinder head should be wiped clean. Tighten
plugs to the proper torque value
plug terminals are fully seated on the spark plugs.
When spark plug leads are removed, be sure they are
replaced in the correct firing order
DANGER!
•
Avoid abusive handling that could crack the
spark plug's ceramic body (A). Damaged spark
plugs can emit external sparks that could ignite
any fuel vapors in the engine compartment,
resulting in fire or explosion.
•
Do not operate engine if spark plug boots or
high-tension leads are torn or cracked. This con-
dition could allow external sparks which could
ignite any fuel vapors in the engine compart-
ment, resulting in fire or explosion.

Checking and Changing Spark Plugs

1. Twist and pull only on the spark plug wire boot
(pulling on wire may cause separation of the core
of the wire).
2. Remove spark plugs using a 5/8-inch spark plug
socket or a 5/8-inch box wrench. Use care to
avoid cracking the spark plug insulators (D).
3. Carefully inspect the insulators and electrodes of
all spark plugs.
Replace any spark plug which has a cracked
or broken insulator or which has loose elec-
trodes (B).
If the insulator is worn away around the center
electrode (C), or the electrodes are burned or
worn, the spark plug is worn out and should
be discarded.
Spark plugs that are in good condition, except
for carbon or oxide deposits, should be thor-
oughly cleaned and gapped.
1. For additional information, see Technical Data on
page 115.
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. Make sure the spark
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.
VPA 7748131 English 09-2007