jcb G20 Operator's Manual page 135

Lubricating oil sludge excessive.
Fuel in the lubricating oil, engine operating too cold.
Electrical sensor fault
One or more engine injector worn or malfunctioning.
Cause
Oil level incorrect.
Incorrect lubricating oil (specification of viscosity).
Pressure sensor or gauge fault.
Lubricating oil filter blocked.
Lubricating oil filter drain down valve not fitted.
Suction pump pressure relief valve stuck open.
Oil pump pressure relief valve stuck open.
Lubricating oil pump worn.
Cause
Incorrect lubricating oil (specification of viscosity).
Pressure sensor or gauge fault.
Engine running too cold.
Oil pump pressure relief valve stuck closed.
Coolant
Cause
Incorrect coolant level.
Coolant leaking from engine radiator or block heater. Visually inspect the radiator heater, hoses and con-
External engine coolant leak.
Overheating or compression gases leaking, resulting
in loss through the radiator overflow.
If equipped, transmission cooler leak.
If the engine is coolant aftercooled, aftercooler leak.
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Change oil and filter.
Review oil and filter change period. If operating in ar-
duous applications, change more frequently.
Make sure the correct lubricating oil is being used.
Review the operation for excessive idling resulting in
the engine running below normal temperature.
Review the operation for excessive idling resulting in
the engine running below normal temperature.
Have oil sample analysed. Repair engine as re-
quired.
Table 41. Lubricating Oil - Pressure Low
Remedy
Check oil level.
Make sure the correct lubricating oil is being used.
Check for reduced viscosity from dilution with fuel.
Fuel dilution in lubricating oil can originate from a de-
fective high pressure fuel pump driveshaft seal.
Review oil and filter change period. If operating in ar-
duous applications, change more frequently.
Change lubricating oil filter.
Change lubricating oil filter.
Review oil and filter change period. If operating in ar-
duous applications, change more frequently.
Change lubricating oil filter.
Check/replace seal.
Replace oil pump assembly.
Replace oil pump assembly.
Table 42. Lubricating Oil - Pressure High
Remedy
Make sure the correct lubricating oil is being used.
Review oil and filter change period. If operating in ar-
duous applications, change more frequently.
Verify the pressure sensor is functioning correctly.
Refer to Table 45.
Replace oil pump assembly.
Table 43. Coolant - Loss
Remedy
Check the level.
nection to locate the leak.
Visually inspect the engine and components for seal,
gasket hose connection leaks. Make sure all hose
clips are in good condition and torqued to the recom-
mended figure.
Refer to Table 44.
Check for mixing of coolant and transmission fluid.
Check/replace the aftercooler. Look for coolant in the
intake manifold and in the oil.
9831/0650-3
Maintenance
Fault-Finding
128