Engine Oil Pressure Is High - Perkins 4008-30 SD8 Systems Operation, Testing And Adjustment

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Lubrication System
Low Engine Oil Level
Check the engine oil level. If the engine oil level is too
far below the suction tube, the engine oil pump
cannot supply enough lubrication for the engine
components. If the engine oil level is low, add engine
oil in order to obtain the correct level. For the correct
engine oil to use, refer to Operation and Maintenance
Manual, "Refill Capacities" and Operation and
Maintenance Manual, "Fluid Recommendations".
Engine Oil Pressure Gauge
Refer to Testing and Adjusting, "Engine Oil Pressure
- Test". If the engine oil pressure gauge is incorrect,
install a new gauge.
Contaminated Engine Oil
Engine oil that is contaminated with another liquid will
cause low engine oil pressure. High engine oil level
can be an indication of contamination. Determine the
reason for contamination of the engine oil and make
the necessary repairs. Change the engine oil and the
engine oil filters. For the correct engine oil to use,
refer to Operation and Maintenance Manual, "Fluid
Recommendations".
Improper Circulation of the Engine
Oil
Several factors could cause improper circulation of
the engine oil:
• The engine oil filters are clogged. Replace the
engine oil filters.
• A line or a passage for the engine oil is
disconnected or broken. Replace the line or clear
the passage.
• The engine oil cooler is clogged. Thoroughly clean
the engine oil cooler.
• There is a problem with a piston cooling jet. The
piston cooling jets direct engine oil toward the
bottom of the pistons in order to cool the pistons.
This also provides lubrication for the piston pin.
Breakage, a restriction, or incorrect installation of
a piston cooling jet will cause seizure of the piston.
• The inlet screen of the suction tube for the engine
oil pump can have a restriction. This restriction
can cause cavitation and a loss of engine oil
pressure. Check the inlet screen on the suction
tube and remove any material that may be
restricting engine oil flow.
• The suction tube is drawing in air. Check the joints
of the suction tube for cracks or a damaged O-ring
seal.
• There is a problem with the engine oil pump.
Check the gears of the engine oil pump for
excessive wear. Engine oil pressure is reduced
when gears in the engine oil pump have too much
wear.
NOTICE
Perkins oil filters are manufactured to Perkins specifi-
cations. Use of an oil filter that is not recommended
by Perkins could result in severe damage to the en-
gine bearings, crankshaft, etc., as a result of the larg-
er waste particles from unfiltered oil entering the
engine lubricating system. Only use oil filters recom-
mended by Perkins.
Worn Components
Excessive clearance at the crankshaft or camshaft
bearings will cause low engine oil pressure. Also,
inspect the clearance between the rocker arm shafts
and the rocker arms. Check the engine components
for excessive clearance.

Engine Oil Pressure is High

NOTICE
Keep all parts clean from contaminants.
Contaminants may cause rapid wear and shortened
component life.
NOTICE
Care must be taken to ensure that fluids are con-
tained during performance of inspection, mainte-
nance, testing, adjusting and repair of the product.
Be prepared to collect the fluid with suitable contain-
ers before opening any compartment or disassem-
bling any component containing fluids.
Dispose of all fluids according to local regulations
and mandates.
Engine oil pressure will be high if the engine oil
bypass valves become stuck in the closed position
and the engine oil flow is restricted. Foreign matter in
the engine oil system could be the cause for the
restriction of the oil flow and the movement of the
engine oil bypass valves. If the engine oil bypass
valves are stuck in the closed position, remove each
bypass valve and clean each bypass valve in order to
correct this problem. You must also clean each
bypass valve bore. Install new engine oil filters. New
engine oil filters will prevent more debris from
causing this problem. For information on the repair of
the engine oil filter bypass valve, refer to
Disassembly and Assembly, "Engine Oil Filter Base -
Disassemble".
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