Yanmar 3JH4E Service Manual page 68

TROUBLE AND TROUBLESHOOTING
(I-1) Tighten nuts.
(I-2) Tighten nuts and insert pins.
(I-3) Remove adjustment liner and adjust aperture,
or replace.
(I-4) Check teeth, shaft, and pushrod of gear
for wear. Replace where necessary.
(I) Abnormal noise
(1) Loose flywheel installment bolt
(2) Loose crank pin bearing bolt
(3) Worn crank pin metal
(4) Faulty gear meshing
(1) Cooling water temperature
has risen
(2) Overloading
(3) Faulty lube oil
temperature
adjustment valve
(IV) Lube oil temperature is too high
(IV-1) Adjust the amount of returning water or
check the cooling water pump and lap valves.
(IV-2) Reduce load.
(IV-3) Clean and adjust.
(II-1) Tighten adjustment valve.
(II-2) Check and repair.
(II-3) Clean.
(II-4) Repair.
(II) Low fuel oil pressure
(1) Loose pressure adjustment
(2) Damaged supply pump
(3) Clogged filter
(4) Leaky pipe
(1) Insufficient amount of cooling water
(2) Trouble with cooling water pump
(3) Amount of water returning
is too great
(4) Clogging in cooling
water system
(V) Cooling water temperature is too high
(V-1) Open closed parts.
(V-2) Check pump and repair.
(V-3) Adjust amount of returning water.
(V-4) Clean.
(V-5) Check suction opening.
(V-6) Reduction load.
(III-1) Clean.
(III-2) Add cooling water.
(III-3) Disassemble and repair or replace.
(III-4) Tighten adjustment valve.
(III-5) Tighten safety valve.
(III-6) Change lube oil.
(III-7) Add lube oil.
(III-8) Replace.
(III) Low lube oil pressure
(1) Clogged lube oil filter
(2) Lube oil temperature is too high
(3) Trouble with lube oil pump
(4) Loose pressure adjustment valve
(1) Clogging in cooling water system
(5) Air in cooling water
(2) Trouble with cooling water pump
(6) Overloading
(3) Cooling water lift is too great
(4) Air in cooling water
(VI) Cooling water pressure is too low
(VI-1) Clean.
(VI-2) Check pump and repair.
(VI-3) Lessen lift or replace pump.
(VI-4) Check suction opening.
(VI-5) Eliminate causes for high cooling water
(VI-6) Check and repair.
Chart 9
MISCELLANEOUS TROUBLE
(5) Oil leakage from pump safety valve
(6) Inadequate viscosity of lube oil
(7) Insufficient amount of lube oil
(8) Faulty pressure gauge
MISCELLANEOUS
TROUBLE
(5) Engine outlet not constricted.
(6) Water leakage from
cooling water joints.
temperature and constrict.