Oil Consumption:diagnosis; Oil Pressure Diagnosis And Testing - GMC chevrolet camaro 2000 Service Manual

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Engine Mechanical - 3~8L
Oil Consumption Diagnosis
An engine that has excessive oil consumption uses
0.9L (1 qt) of oil, or more, within 2,000 mi (3 20.0 km).
The following list indicates the conditions and
corrections of excessive oil consumption:
• An improperly read oil level indicator (dipstick)
- Inspect the oil level while the vehicle is
parked on a level surface.
- Allow adequate drain-down time.
• Improper oil viscosity
- Use the recommended SAE viscosity for
prevailing temperatures.
- Refer to Maintenance and Lubrication for the
proper oil viscosity specifications.
• Continuous high-speed driving
• Severe hauling, such as a trailer. This causes
decreased oil mileage.
• A malfunctioning crankcase ventilation system
• External oil leaks
- Tighten the bolts, as needed.
- Replace the gaskets and seals, as needed.
• Worn or.omitted valve guides and/or valve
stem seals
- Ream the guides.
- Install oversized service valves ancl/or new
valve stem seals.
• Broken or worn piston rings
• Improperly installed or unseated piston rings
• Improperly installed or improperly fitted piston
• Plugged cylinder head gasket oil drain holes
• Damaged intake gaskets
Oil Pressure Diagnosis and Testing
Low
or No Oil Pressure
The following can cause low or no oil pressure:
• Low oil level - fill to the full mark on the oil level
indicator.
• Slow idle speed
• Incorrect or malfunctioning oil pressure switch -,-
replace the oil pressure switch.
• Incorrect or malfunctioning oil pressure gauge-,-
replace the oil pressure gauge.
• Improper oil viscosity or diluted oil
- Install oil of proper viscosity for expected
temperature.
- Install new oil if it is diluted.
• The oil pump is worn or dirty - clean or replace
the oil pump.
• The oil filter is plugged - replace the oil filter.
• The oil pickup screen is loose or plugged -
replace the oil pickup screen.
• A hole in the oil pickup tube - replace the oil
pickup tube.
Engine
• Excessive bearing clearance - replace the
bearings.
• Cracked, porous, or plugged oil galleries -,- repair
or replace the engine block. · ·
• The gallery plugs are missing or improperly
installed - install or repair as necessary ..
• The pressure. regulator valve is: stuck.'
- Check the pressure regulator valve for
sticking in the bore.
- Check the bore for scoring and burrs.
• The camshaft is worn or poorly machined -
replace the camshaft. ·
• Worn valve guides·--'- repair as needed.
Oil Pressure Testing
Tools ,Required
J 25087-C Oil Pressure Test Kit
If the ve.hicle has low oil pressure perform the
following tests.
1. Check the oil level ..
2. Raise the vehicle and remove the oil filter.
3. As$emble the plunger valve in tbe large hole of
J 25087-C base and the hose in the small hole
of J 25087-C base. Connect the gauge to the end
of the hose.
4. Insert the flat side of the rubber plug in the
bypass valve without depressing the bypass valve
itself. ·
5. Install J 25087-C on the filter mounting pad.
J 25087-C
6. Start the engine and check the overall oil
pressure, the oil pressure switch, and for
566977
noisy lifters. The engine should be at operating
temperature before checking the oil pressure. The
oil pressure should be approximately
414kPa (60 psi) at 1850 rpm using
1 OW30 engine oil.
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