Engine Oil Pressure Testing

The
oil pressure or, more precisely, its lack of it – in some parts of the engine may lead to serious problems for the engine. Engine oil pressure decreases with the passage of time (increasing the operational life) for all engines, and this is a result of natural wear and increased clearances. But the abnormal drop in oil pressure in the case of new engines, is often the result of a problem with the engine and needs urgent repair. Leaving the engine oil system problems untreated may exacerbate the problem, and may lead to engine hardening, and then we will need a complete engine change instead of a repair.
Oil pressure source: The oil
pump does not do the work and increase the oil pressure, but the pump only works to pump a continuous amount of oil, but the resistance to oil flow through the oil path is what leads to the formation and raising of the pressure value.  
The factors affecting oil pressure (amount of oil delivered, resistance to oil flow in the tracks (suitable oil viscosity, standard clearances)) are as follows:

• Pump Condition (Standard Clearances)
• Bearing clearances Crankshaft, cam and connecting rod bearings (seat wear or damage)
• Oil viscosity (type and condition of oil)
• temperature (engine, atmosphere)
• Oil pump overpressure protection valve spring (  pressure regulating (relief) valve ) (this valve operates when the pressure exceeds a specified amount of pressure (40 to 60 psi). This allows oil to return to the oil pan lowering the oil pressure in the engine, in order to prevent the oil pressure from reaching a high level that may cause the oil filter to explode or push the oil tracks in the engine block outwards.

Oil pressure problems:

• Low oil pressure  low oil pressure
• High oil pressure  high oil pressure

Symptoms of low engine oil pressure:

• intermittent illumination of the  pressure indicator light   (the warning lamp lights up when the oil pressure is low),
• Noise is heard from the engine (due to poor lubrication, crankshaft bearing wear increases (alloys), clearance increases, and noise increases),
• Difficulty starting the drive (poor lubrication and damage to the crankshaft bearings and connecting rods, which leads to increased friction and difficulty in starting the drive),
• Poor engine performance (increasing the amount of friction inside the engine increases the friction resistance and the loss of engine power)
• Delayed switching off of the oil pressure warning lamp after starting; Before starting the engine (when the ignition is turned and before the starter is started) the oil lamp is lit and takes about one to two seconds to turn off. If the time is increased by more than 2 seconds, this indicates that either the oil filter is clogged and needs to be replaced, either there is an increase in the clearances of the bearings or an increase in the clearances of the oil pump.

Symptoms of high engine oil pressure:

• High reading of the oil pressure gauge
• swollen oil filter
• Operational problems (high pressure may cause the hydraulic jacks to apply more pressure than required and not allow the valves to fully close)

Possible causes of low oil pressure:

• Long life motor
• Clearances greater than standard in main bearings and connecting rod bearings due to wear.
• Crankshaft or camshaft wear
• Damage to the oil pressure sensor module (lower meter reading, or pressure warning light illuminating)
• Damage to the oil pressure sensor electrical circuit (grounded or open)
• A low level (level) of the engine oil, or an increase as well (a low level of the oil in the oil pan allows air to enter the pump. In addition, an increase in the oil level leads to excessive oil contact with the crankshaft when it rotates and the oil turns into foam, and air bubbles enter to the pump with the oil)
• Using oil with low viscosity or low oil viscosity as a result of oil contamination with gasoline
• Blockage in the oil drainer of the oil strainer   (reducing the amount of oil sent)
• Clogged oil filter (clogged oil filter will cause the oil pressure relief valve to open, reducing the pressure value to the set pressure of the oil pressure relief valve)
• Problem with the oil drain valve (valve spring weakened or broken, valve stuck in the open position)
• The presence of a crack or a lack of tightness of the oil intake tube, the connection between the filter and the pump,  pickup tube   (air entry with oil)
• Oil pump clearance problem (oil pump wear or tear)

Possible causes of high oil pressure:

• The pressure relief valve stuck in the closed position.
• Strong spring in pressure relief valve
• Use of high viscosity oil
• Blockage in the oil ducts (damage to the ducts or the presence of impurities in the ducts)
• Oil pressure sensor module damaged (high pressure gauge reading)
• Oil filter blockage (not changing the oil or filter within the specified intervals, increasing the oil usage period)
• Underrated bearing clearances (due to problems arising from engine overhauling and overhauling)

Reasons for conducting an engine oil pressure test: It is
recommended to do an oil pressure test when there is reason to believe that the oil pressure is incorrect or when there is a need to ascertain the condition of the engine. Phenomena that require an oil pressure test:

• poor engine performance
• The oil pressure warning light on the dashboard is cut off
• Excessive noise from the engine
• Difficulty starting management

Procedures before the engine oil pressure test:
Oil pressure problems may not be related to the condition of the engine, so other causes for this can be detected first:

• Check engine oil level
• Checking the work of the pressure value sensor unit

Checking the engine oil level:
Diagnosing the condition of low oil pressure can be started with the  dipstick . Check the oil level to make sure the oil level is correct inside the oil pan (not more or less). If the oil level is low, it may be due to a leak or burning of the oil inside the engine. Adding oil may solve the problem of low pressure, but if the oil level is not maintained, the problem may recur. It also notes through the oil pressure gauge stick the condition of the oil and its appropriate degree of viscosity.
When measuring the oil level, wait at least 15 minutes after turning off the engine to allow the oil to drain back into the oil pan. This ensures that the engine oil level reading is correct. Measuring the oil level immediately after the engine stops will give incorrect (low) readings of the oil level, as most of the oil is still inside the lubrication circuit.
Checking the pressure value sensor unit:
Unplug the unit and note the pressure warning light or dashboard pressure gauge. If the warning light remains lit when the pressure sensor unit is disconnected, this means that there is a ground connection in the oil bulb warning circuit. In the event that the pressure value remains constant in the meter, this means that the problem is in the meter and not the engine.
The oil pressure warning lamp is connected to a pressure valve. The pressure valve sends a signal when the pressure reaches less than 5 pounds per square inch (3.5 kPa), this value varies from one engine to another according to its specifications.
Engine oil pressure test: The
device used: It
uses a pressure gauge (mechanical counter) and a tube (Li) that can withstand high pressure to perform the test, to connect the device to the engine. The meter range should be from 0 to 100 psi (690 kPa).
Connecting the device to the engine: The
 tube is connected to the cylinder block in the area from which the engine oil pressure is measured, such as a sensor hole (pressure signal transmitter), the main oil line, or the base of the oil filter. The most suitable area for sizing different engines is specified in the maintenance catalog for those engines.
Precautions to be taken when performing the test:

• The oil pressure test is carried out after the engine oil and oil filter have been changed (so that the condition of the oil and filter does not affect the test results).
• The engine must be running to reach operating temperature. Operating temperature is also indicated in the catalog. When the operating temperature is reached, the engine must be started at the stated speed for the test.

Steps to take the test:

• You must ensure the quality of the connection, so that there is no oil leakage that limits pressure
• The oil pressure data should be reviewed from the maintenance manual for the vehicle under test.
• The test shall be carried out at an empty load speed (approximately 2000 rpm or as specified in the Service Catalog)
• Take a meter reading.
• The reading is compared to the standard values ​​provided in the catalog.

Analysis of test results:
Pressure gauge reading depends on operating life, engine type, and is in the range of 20 to 30 psi (138-207 kPa) at an empty load speed, 40 to 60 psi (276-413 kPa). ) at normal travel speed. The standard pressure specifications of the motor under test should be consulted to compare the test results.