Step by step guide on how to troubleshoot and repair low oil pressure, this
information pertains to all internal combustion engines.
Difficulty Scale: 5 of 10
Tools and Supplies Needed
- Socket set
- Wrench Set
- Fluid catch basin
- Manual oil pressure gauge
- Protective gloves and eye wear
Start with the car on level ground, in park with the emergency brake set.
- To verify the engine oil pressure is
low, start the engine (cold) and observe the gauge or light.
Low Oil Pressure
Step 2 - Using the engine oil dip stick, check
the oil level of the engine and ensure a proper level.
Step 3 - The oil pressure switch is designed to
send feedback data to the gauge or computer. These switches can go bad causing
the gauge or light to show a false reading, remove the switch and insert a
manual gauge to the engine and restart the engine. The gauge should read between
25 and 45 pounds.
Oil Pressure Switch
Step 4 - The oil pump uses a screen to keep out
impurities before entering the pump. If this screen becomes plugged with sludge
due to lack of maintenance, the pump will scavenge causing low pressure. (Engine
oil pan removed while turned over.)
Step 5 - The oil pump is also designed with an
oil pressure relief valve and spring which regulates pressure. If this valve
becomes faulty caused by a broken pressure spring the pump will have low oil
Oil Pump Pick-Up Screen
Oil Pressure Relief Valve
Step 6 - An engine bearing is designed to
support the crankshaft and other various engine parts while in motion. When
these bearings wear, they can allow more oil to escape causing low oil pressure,
this is a sign the engine has worn out and replacement or rebuilding is needed.
Step 7 - If the engine has no oil pressure,
suspect the oil pump drive, some manufactures use a belt to drive the pump which
are prone to failure.
Engine oil is used
to cool and lubricate bearing and machined surfaces. Without oil pressure an engine will experience extreme internal
engine damage due to heat caused by friction. All engines run on a pre-set pressure
that cannot be adjusted. This pressure will vary depending on engine speed, temperature
and weight oil. As a rule of thumb, the engine oil pressure gauge shouldn't drop
below 1/4 or exceed 3/4 pressure of the gauge.
Oil Pump Drive Belt
Article first published 2017-01-26