Checking Engine Oil Pressure; Trochoid Oil Pump; 3Tnv82A To 4Tnv88 Oil Pump Components - Yanmar 3TNV82A-B Service Manual

Checking Engine Oil Pressure

CHECKING ENGINE OIL
PRESSURE
Perform an engine oil pressure check if there is any
indication of low oil pressure such as the oil
pressure indicator is on or the oil pressure gauge
indicates low oil pressure. See Engine Oil Pressure
on page 9-5.
1. Disconnect the wire lead from the oil pressure
switch or sending unit (Figure 9-2, (1)).
(1)
Figure 9-2
2. Remove the oil pressure switch.
3. Install a mechanical oil pressure gauge in the
oil pressure switch port.
4. Start the engine:
• If the mechanical oil pressure test gauge
indicates good oil pressure, replace the faulty
oil pressure switch or sending unit, or faulty
machine oil pressure gauge in instrument
panel.
• If the mechanical oil pressure test gauge
indicates low oil pressure, troubleshoot the
lubrication system to locate the cause of the
low oil pressure. See Failure Diagnosis Table
on page 15-191. Repair as necessary.
TNV DI Service Manual

TROCHOID OIL PUMP

3TNV82A TO 4TNV88
Components
On these model engines, the oil pump is located
inside the front gear case cover and is driven by a
boss on the front crankshaft gear. You must remove
the front gear case cover to gain access to the oil
pump.
(3)
0000028B
1 – Crankshaft
2 – Oil Pump Cover
3 – Oil Pressure Regulator
4 – Gear Case Cover
5 – Outer Rotor
6 – Inner Rotor
LUBRICATION SYSTEM
Oil Pump
(1)
(2) (5) (6)
(4)
Figure 9-3
0000075A
9-9