Page 482 - Foton Workshop Manual - Auman EST-M

DI - 428 Diagnosis - Mechanical fault diagnosis

Failure phenomenon Possible reason Failure elimination

Coolant temperature lower than Refer to coolant temperature lower than normal
specification value failure diagnosis

Engine oil not meeting the specification
Replace the engine oil or filter
of working condition
Measure the engine oil pressure Run the engine
Engine oil pressure switch, pressure gauge
and compare the reading with the vehicle
or sensor failed or installation position not
pressure gauge or engine oil pressure
Engine oil pressure high correct
sensor/switch

Measure the engine oil pressure Run the engine
Failure of oil pressure sensor/switch or and compare the reading with the vehicle
circuit installed in the engine pressure gauge or engine oil pressure
sensor/switch

Failure in the engine oil pressure regulator Check if the installed engine oil pump part
of main oil way number is correct
Engine oil level higher or lower than Check the engine oil level. If necessary, fill in or
specification discharge the engine oil

Check if there is external leakage in the engine.
Engine oil leaking Tighten the crews, pipe plugs and joint. If
necessary, replace the gasket

Engine oil not meeting the specification
Replace the engine oil or filter
of working condition
Refer to engine oil contamination failure
Engine oil contaminated by coolant or fuel
diagnosis

Coolant temperature higher than Refer to coolant temperature higher than normal
specification value—graually too hot failure diagnosis
Engine oil pressure low
Failure in the engine oil pressure regulator Check the main oil way engine oil pressure
of main oil way regulator assembly

Engine oil suction pipe or transfer pipe Dismount and check the oil sump or oil suction
loose or broken, gasket or O-ring leaking pipe
Dismount the front gear chamber to check if the
The oil pressure sensor/switch or pipeline
coolant blocks the engine oil pressure
on the engine is blocked
sensor/switch terminal

Engine oil pump failed Check the engine oil pump

Engine oil cooler blocked Check the engine oil cooler

Engine oil temperature exceeding Refer to engine oil temperature higher than
specification specification failure diagnosis

DI-428