Onan MJA Series Service Manual page 66

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. OIL SYSTEM
TROUBLE-SHOOTING
CHART 6,
OIL SYSTEM
TROUBLE POSSIBLE CAUSE REMEDY
Diluted oil Leaky fuel pump Rebuild pump
diaphragm
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Worn compression rings Inspect rings and
or scored cylinders cylinder walls
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Sludge in
Dirty oil filter Replace oil filter:
crankcase adjust oil filter
service periods
:
Run for long periods Review operating
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at idle procedures
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Excess oil con- Worn or sticking piston
rings
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~~~:~~~kvlight
j •.
exhaust
Defective breather valve Clean valve
. _ .
Oil too light or diluted
Engine overheating
See Sect 3.1 I
Excess oil con-
Leaking oil seals
Inspect crankshaft
sumption; no
front and rear oil
cbange in exhaust
seals
Leaky oil base gasket Check for leaks
around gasket. Re ­
place if necessary
Defective breather valve Clean valve, Sect
3.5.7
Low -oil pressure
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Worn bearings Rebuild engine
Oil by-pass stuck open
Oil supply low
Worn oil pump
- - - ­
Check compression.
Clean or replace
rings
Replace with proper
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gradeo! oil - if
diluted check for
cause
Clean by-pass valve
Add oil. Check cause
of oil consumption
InstaU new pump
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