BASE ENGINE MISFIRE WITH ABNORMAL INTERNAL LOWER ENGINE NOISES
A damaged crankshaft reluctor wheel can
result in different symptoms depending on the
severity and location of the damage.
Systems with electronic
communications, DIS or coil per
cylinder, and severe reluctor ring
damage may exhibit periodic loss of
crankshaft position, stop delivering a
signal, and then sync the crankshaft
position.
Systems with electronic communication,
DIS or coil per cylinder, and slight
reluctor ring damage may exhibit no loss
of crankshaft position and no misfire
may occur. However, a P0300 DTC
may be set.
Systems with mechanical
communications, high voltage switch,
and severe reluctor ring damage may
cause additional pulses and effect fuel
and spark delivery to the point of
generating a P0300 DTC or P0336.
required.
Cause
Correction
Abnormalities, such as severe cracking,
bumps or missing areas in the accessory drive
belt
Abnormalities in the accessory drive system
and/or components may cause engine RPM
variations, noises similar to a faulty lower
engine and also lead to a misfire condition. A
misfire code may be present without an
actual misfire condition.
Replace the drive belt. Refer to Drive Belt
Replacement - Accessory.
Worn, damaged, or mis-aligned accessory
drive components or excessive pulley runout
A misfire code may be present without an
Inspect the components and repair or replace,
as required.
2008 Hummer H3
2008 ENGINE Engine Mechanical - 5.3L - H3