Reduced oil pressure
Low oil pressure can manifest itself in various ways. If the vehicle is equipped with an oil pressure gauge, then the most obvious indication of low pressure will be low readings on that gauge. But before you suspect wear on a large number of engine metal parts, do some checks.
Make sure the oil pressure warning light is working properly. Make sure that the problem is really related to low oil pressure by removing the oil pressure sensor and installing an oil pressure gauge in the hole for it. If you do not have such a pressure gauge, then you can rent it in the workshop.
The oil pressure you should expect will change with the oil temperature. The oil temperature will change with engine temperature. It is possible that the engine will be cold when you perform this test. Cold oil, by definition, gives higher pressure than warm oil. This will also be true when using multigrade oils.
When a mechanical oil pressure gauge is connected to the port where the oil pressure gauge was installed, start the engine immediately after starting the engine and before actually checking the oil pressure, check the gauge connection and make sure there are no oil leaks. Even small leaks on some pressure gauges can lead to an error in the readings of the device. If no leaks are found, compare the oil pressure with the values given in the engine data sheet.
This oil sump shows the results of too infrequent engine oil changes. The layer of deposits on the bottom of the crankcase has a thickness of 1-1.5 cm.