Doosan DA40 - High oil pressure (engine warmed up); Abnormal wear (liner, piston rings, etc.)

Engine
SHOP MANUAL
Ch 1 page 235
High oil pressure (engine warmed up)
Abnormal wear (liner, piston rings, etc.)
Eect Cause Trouble shooting Action
Gauge indicates
high pressure
Defective sensor/instru-
ment
Take a reading of the oil pressure on the warmed-
up engine using a mechanical pressure gauge
directly on the engine:
Minimum 1 bar at 800 r/min.
Maximum 6 bar > 800 r/min.
Note! Single-speed engines must not be tested
at 800 r/min. Risk of damage to the
exible coupling
Oil viscosity too high
- Choose a viscosity that
is suitable for the ambi-
ent temperature
Gauge indicates
high pressure
Incorrectly adjusted oil
relief valve
- 1 shim = 0.2 bar
(screw adjustment on
14-series engines)
Piston in oil relief valve
jammed in closed posi-
tion
Valve in oil duct to pis-
ton cooling nozzles is
binding
Eect Cause Trouble shooting Action
Short service life
Unclean induction air
due to inadequate lter-
ing (wrongly dimen-
sioned air lter)
Wear ridge (ring travel
shoulder) at piston top
dead centre
- Fit a more ecient air
lter
Unclean intake air due to
leakage in intake piping
Wrong grade of oil, pol-
ishing damage
Changing of lters and
oil has been neglected
Low coolant tempera-
ture (cold engine)
Excessive sulphur con-
tent in fuel
- Change the fuel
- Change to oil with a
higher base number
- Shorter oil change
intervals
Defective injector
(causes oil lm to be
washed o)