jcb G20 Operator's Manual page 133

Turbocharger wastegate faulty. (Turbocharged ma-
chines only).
Turbocharger malfunction.
Electrical sensor fault.
One or more fuel injector worn or malfunctioning.
Engine compression low in one or more cylinders.
Smokes under load at all speeds, but mainly low to
mid speed range.
Table 35. Engine - Exhaust Smoke Excessive (White/Blue Smoke)
Cause
Improper starting procedure.
Fuel is contaminated or incorrect grade diesel fuel
used.
Oil level incorrect.
Diesel or hydraulic oil in sump.
Coolant temperature too low (over-cooling) - light
blue or white high speed/light load.
Electrical sensor fault.
One or more engine injector worn or malfunctioning. -
white/ blue smoke at operating temperature.
Coolant leaking into combustion chamber.
Leaking valve stem seals - evident after long idle pe-
riod and then acceleration.
One or more fuel injector worn or malfunctioning.
Piston rings not sealing - evident with persistent blue
smoke at all speeds/load.
Cause
Stop switch or stop switch electrical system failure.
Fuel
Cause
Additional load on engine.
Operator technique.
Fuel leaks.
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Repair or replace wastegate.
Replace Turbocharger.
Check the electrical connections at the sensors.
Check the electrical connections at the injectors.
Check the engine compression.
Remedy
Verify proper starting procedure.
Stop the engine.
Replace the fuel filters. Operate the engine with a
temporary supply of the correct grade of clean fuel.
Monitor the engine performance.
WARNING: Dirty fuel will cause damage to the fuel
injection pump and injectors.
Check oil level.
Check oil consistency. If oil contamination is suspect-
ed check equipment suck as PTO pump for hydraulic
oil leaks past the seal into the engine. Drain, flush
and fill with clean oil.
Refer to Table 45.
Check the electrical connections at the sensors.
Check the electrical connections at the injectors.
Refer to Table 43.
Replace valve seals.
Check the electrical connections at the injectors.
Check the engine compression.
Table 36. Engine - Will Not Shut Off
Remedy
Check the operation of the stop switch. Check the
correct electrical wires for open or short circuits.
Table 37. Fuel - Consumption Excessive
Remedy
Check/repair accessories and vehicle components.
Refer to the equipment manufacturer's procedures.
Review operation for correct gear shifts, deceleration
and idling.
Check for external leaks at the fuel tank, fuel lines,
filters and lift pump.
WARNING: DO NOT repair defective fuel lines. If
there is a fuel leak remove and discard the neces-
sary components and install new ones.
9831/0650-3
Maintenance
Fault-Finding
126