Komatsu ecot3 PC300-8, Shop Manual

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40 Troubleshooting SEN02634-02
PC300, 350-8
15
S-8 Oil consumption is excessive (or exhaust smoke is blue) 1
General causes why oil consumption is excessive
• Abnormal consumption of oil
• Long-time operation of engine at low idle or high idle
(Do not run engine at idle for more than 20 minutes continuously)
• External leakage of oil
• Wear of pats in lubrication system
Cause
D
u
st
s
u
cked
in
f
rom
in
ta
k
e
s
yst
em
W
o
rn
, damaged
valve
(s
te
m
, guide,
seal)
T
u
rbochar
g
er
Clogged
br
eat
h
er
, breat
her hose
Brok
en pist
on
ring
Exc
e
ssiv
e
wear
of
pist
on r
ing
,
cylinder
liner
W
o
rn
, damaged
rear oil
se
al
Brok
en oil c
ooler
O
il
lea
k
age f
rom
oil c
ooler
Oi
l
le
a
k
age from
oil filt
er
O
il
lea
k
age f
rom
oil piping
O
il
lea
k
age f
rom
oil dr
ain plug
O
il l
ea
k
age
fr
om
oil
pan,
cylinder head,
et
c.
W
o
rn
s
e
al
at
t
u
rbocharg
er end
W
or
n
s
eal
at
blower end
Q
u
est
ions
Confirm recent repair history
Degree of use of
machine
Operated for long period
E E E E
Oil consumption suddenly increased
w Q
Oil must be added more frequently
w Q
Oil becomes contaminated quickly
Q Q w
Outside of engine is dirty with oil
w w w w w
There are loose piping clamps in intake system
w
Chec
k it
ems
Inside of turbocharger intake outlet pipe is dirty with oil
w
Inside of turbocharger exhaust outlet pipe is dirty with oil
Q w
There is oil in coolant
w
Oil level in clutch or damper chamber of applicable machine is high
w
Exhaust smoke is blue under light load
w w
Amount of blow-by gas
Excessive
Q Q w w
None
w
T
roubleshoot
in
g
When intake manifold is removed, dust is found inside
q
When intake manifold is removed, inside is found to be dirty abnormally
q
Excessive play of turbocharger shaft
q q
Check breather and breather hose directly
q
When compression pressure is measured, it is found to be low
q q
Inspect rear oil seal directly
q
Pressure-tightness test of oil cooler shows there is leakage
q q
There is external leakage of oil from engine
q q q q
Remedy
Correct Correct Replace Replace Cl
e
a
n
Replace Replace Correct Replace Replace Correct Correct Correct Correct