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. |
• | Incorrect or malfunctioning oil pressure switch -- replace
the oil pressure switch. |
• | Incorrect or malfunctioning oil pressure gage -- replace
the oil pressure gage. |
• | 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. |
• | 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 vehicle has low oil pressure perform the following tests.
- Check the oil level.
- Raise the vehicle and remove the oil filter.
- Assemble the plunger valve in the 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.
- Insert the flat side of the rubber plug in the bypass valve without
depressing the bypass valve itself.
- Install J 25087-C
on the filter mounting pad.
- Start the engine and check
the overall oil pressure, the oil pressure switch, and for 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 10W30 engine oil.
- If adequate oil pressure is indicated, check the oil pressure
switch.
- If a low reading is indicated, press the valve on the tester base
to isolate the oil pump and/or its components from the lubricating system.
An adequate reading at this time indicates a good pump and the previous
low pressure was due to worn bearings, etc. A low reading while pressing
the valve would indicate a faulty pump.