Oil light flickers at traffic light stop. Engine at about 500RPM

Low pressure when at idle, after the engine has warmed up and the oil has thinned, indicates that the oil pump is worn and needs to be replaced.

Coolant fluid is made to avoid the freezing of the motor.

Clean the throttle body inside and the idle air control motor.This will help.

Sorry to say the oil light may be for low oil pressure, not necessarily low oil level. If the oil pressure is low, you are wearing out the bearings and engine parts at a very fast pace.

most have an idle stop screw thats adjustable with a phillips screwdrivewr or a nutdriver head..need to adjust this to between 750-800 minimum..your oil light will go out and proper rpm on the alternator will be achieved..

There is a possibility that the oil pressure sensor wire located on the engine block is either incorrectly fitted or the wire is off completely and touches an earth (negative) source, causing your warning light to occasionally flicker

Take to AutoZone for free check

Test the oil pressure, if too low, repair the engine, if normal replace the pressure sending unit .

If your engine is free to move around, your engine may be losing rotational force to engine twist. Technically, when there is a sudden loss of rotational power in the engine rotating assembly, this could cause the oil pump to stop rotating for a split second. however, there are many more reasons that you need to get the mont replaced anyway.