Stop engine oil presssure low warning

The low oil pressure warning lamp will illuminate anytime the ignition switch is turned to the ON position without the engine running. When the engine is running, the light also illuminates if the engine oil pressure drops below a safe oil pressure level. To test the system, perform the following:
If the oil pressure light does not work, perform the following:

1. Turn the ignition switch to the ON position.
2. If the lamp does not light, check for a broken or disconnected wire around the engine and oil pressure sending unit switch.
3. If the wire at the connector checks out OK, pull the connector loose from the switch and, with a jumper wire, ground the connector to the engine.
4. With the ignition switch turned to the ON position, check the warning lamp. If the lamp lights, make sure the oil pressure switch is properly grounded in the cylinder block, and if so replace the oil pressure switch. If the lamp still fails to light, check for a burned out lamp or disconnected socket in the instrument cluster.

To diagnose an oil pressure light that stays on, perform the following:

1. Check the engine oil level and top off as necessary. If the engine was 2 or more quarts low on oil, test start the engine after topping off the oil level and recheck the oil pressure light operation. If the light stays on, stop the engine immediately and go to the next step.
2. Disconnect the wire at the sending unit, then turn the ignition switch to theON position. If the light remains on, check the wire from the sending unit to the gauge for being shorted to ground and repair as necessary. If the light goes out, turn the ignition switch OFF and go to the next step.
3. Replace the oil pressure sending switch with a known good switch.
4. Start the engine and check the oil pressure light operation. If the light stays on with the engine running, stop the engine immediately to avoid severe engine damage until the cause of the problem can be determined.

WARNING
If the oil pressure light remains on while the engine is started, stop the engine immediately. Do not operate the engine until the cause of the problem can be determined. Operating an engine with low oil pressure will cause severe internal damage.

Possible causes for an oil pressure light to stay on are:


Pinched or grounded sensor wireDefective oil pressure sending unitRestricted or severely leaking oil filterExcessive internal engine bearing clearance.Insufficient or severely contaminated engine oilBlocked oil pump pickup screen or severely worn oil pump

That depends on the type of oil warning light being displayed. There are 2 types of warning lights

1. Low oil pressure light which all cars have
2. low oil level light which some cars have.

Low OIL PRESSURE warning means the oil pressure is below minimum and when this happens there will be insufficient lubrication of many engine parts because sufficient oil cannot get to all parts of the engine it is required to lubricate. Until the cause is identified and rectified the warning light will remain. If you run your engine with low oil pressure you will cause expensive damage to internal engine components.

Low OIL LEVEL warning means the oil in the sump has dropped to a dangerously low level (which may be due to an oil leak or abnormal oil consumption by the engine.) This warning means the oil level needs to be topped up and the warning will stay displayed until you top up the oil. Running the engine with low oil will cause expensive engine damage.
Since it is a 2 minute job, Oil levels should be checked fortnightly as a minimum, together with radiator coolant and power steering fluid levels, if you run the car most days each week as most people do.

It is possible for a warning light to remain displayed when the cause has been dealt with because there is a problem with the sender unit. However it needs to be established with alternative checks that the problem has been fixed before investigating if there is a problem with the warning light itself.

The pressure regulator in the oil pump may not be working, the idle speed may be too low and there may be a lot of wear on internal engine parts lowering oil pressure

Check to see you have oil up to full on dipstick . The high pressure pump picks up oil at the top level so if oil starts to get to low engine will stop before engine damage . The high pressure pump is what makes the injectors fire . Also check the wires that go thru valve cover some times they burn up and you can smell the burn thru the oil filler cap .

ck the oil first same answer as before

I see more than one issue in your story. Its possible the computer lost memory and will need to relearn. But that would not explain the knocking noise. The oil pressure warning might explain the noise if oil pressure really is low. Running without the belt for even 5 min would not cause the problems you describe.
I would focus on the low oil pressure warning and the noise first.

Make sure oil level is full, possible faulty oil pressure sender. replace sender and recheck, if warning still comes up, possible internal engine issue.

car needs oil pressure or bearings will wear out in short time. Do not drive or start engine with this light on. Might only be pressure sending unit. Can replace sending unit and start briefly to see if problem resolves. If light still stays on, shut off engine and have oil pump replaced.

The yellow symbol with a line under it means only to warn you if the engine oil level is low when its running. If its RED sign then this is your low engine oil pressure warning light.

replace the faulty oil pressure sending unit.