Oil light flashing?

This could be a couple things but the most common cause of low pressure on an older vehicle is it is just getting worn out. The pressure in an engine is created by the pump forcing oil through the tight passages in the oil system. When those tolerances get larger the pressure drops. Then at idle and low RPM situations the pressure drops far enough to turn the light on.

Here is a guide that talks about this:

https://www.2carpros.com/articles/high-or-low-engine-oil-pressure

Next we need to check a couple things. First is to see if the pressure sensor is accurate because the other possible causes are a sensor issue, pump issue, or wrong oil (too thin).

So if we hook up a mechanical gauge and it is the same and showing low then we know the sensor is not the issue. So that means it is the pump or the engine is just worn

I attached info on how to do this test.

If you find out that the pressure is low at idle, I would just use an oil thickener so that it takes up that difference in the bearings. If the light still comes on, then the pump is the issue.

Let us know what questions you have. Thanks

Sounds like low oil pressure to me. Have the oil checked and if stays on she should not drive it.