General Information; Oil Pump Pressure Test - Hummer H1 Service Manual

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OIL PUMP PRESSURE TEST

Connect the pressure test gauge to the transmitter fitting in the
valley of the block. Pressure should be a minimum of 6 psi (41
kPa) at hot idle and increase to 30 psi (207 kPa) at 2000 rpm.
Low pressures at both test ranges with correct oil level indi-
cate:
¥ Pump pickup strainer or tube loose
¥ Pump pressure relief valve or spring problem
¥ Pump gears worn, chipped
¥ Pump shaft worn, slipping
¥ Oil galley plug loose, missing
¥ Main bearings severely worn
¥ Cam bearing turned (spun) or misaligned
ENGINE DIAGNOSIS

General Information

The diagnosis charts describe common faults that may occur.
Potential causes are listed in order of probability. Although the
charts list frequent causes for specific engine related problems,
they do not cover every possible cause. The charts are intended
to serve as guides only.
The diagnosis information in this section is aimed at solving
engine mechanical problems with normal shop diagnostic
equipment.
05745159
FUSE
TO
IGNITION
SWITCH
00-S02-001
Figure 2-6: Checking Current at Each Glow Plug
TO
AMMETER
IGNITION
SWITCH
FUSE
TO
STARTER
POS. STUD
FUSIBLE
LINK
Engine 2-7