Okay, so I did my first ever oil change on my own this week and had a scary experience. I drained and then added the oil as I should and when I checked it after bringing the engine in operating temp, the dipstick said that I had overfilled it (pulled out, cleaned, put in, over the second dot; engine off, level surface - actually this is what was wrong I later realized since the car was still on jack stands).
So I did what a reasonable engineer would do: drain some oil. Checked a second time, still same results. Drained some more, and this time after a few seconds, the drain spout of liquid became smaller, and I got worried that I had drained too much.
I checked this time, readings were puzzling. Sometimes it said too much still (impossible), sometimes it said too little, sometimes it just had some oil on the side of the dipstick and nothing on the center which confused me. I called up a petrolhead friend of mine and he also couldn't figure it. But when I switched engine on to heat up, I saw the dreaded CEL and a RED engine oil low warning. I switched the engine off, and added whatever more oil I had left (<0.3 quarts).
On a restart the red light was gone but the CEL was still there. The friend said that it might take some time for it to calibrate again but since the engine oil light it gone, it should be good enough to drive to a nearby shop and just have them look at it. Surely later in the night, I checked and the CEL was gone so I was relieved.
Since the CEL was gone, I thought it should be okay to take it to the shop where I was gonna get a brake fluid flush anyways. It was 10 miles from my place, with some freeway and some city driving involved. On my way, just before the freeway, the CEL went on again. This had me worried, but I committed to it still. And then at some point along the way the YELLOW low engine oil light went up. I carefully, very carefully, made it to the shop where they had to top off with 4 quarts of oil.
They cleared the CEL codes - they found two, one for low engine oil, and the other (yikes!) for low enginer oil pressure. Q1) Does anyone know if the low pressure was just because it was low pressure at some point or was it because it was actively low pressure at the point it was checked?
Also, along the way on a left turn traffic light, I experienced the car bounce front to back. Normally, if it is due to fast-moving traffic in the adjacent straight lane, the car moves side to side. Maybe I was just being paranoid because I was hella anxious. Q2) But is that something that could happen due to engine misfiring or grinding because of low engine oil?
The car still purrs perfectly and the shop person said it is fine and I should not have damaged anything. But I just wanted to take opinions here if I should get any diagnostics done here.
Just for context, my 2018 Mazda6 has two oil lights - one RED which means low oil pressure, and one YELLOW which means low oil levels. I drove only with YELLOW, and the RED one was for a few seconds when I idled
