Hey guys, so last night I was driving when I got a Oil pressure warning light and to stop the car. Pulled over to a gas station (I'm not very savvy when it comes to cars btw) and thought maybe it meant low oil. Checked the oil dipstick (didn't realize you want it in between the 2 bends, I thought it was between the 2 orange notches rofl...) and thought it was basically empty (I think it was actually pretty low even though I was using the wrong marker). So I bought 3 quarts of non-synthetic 5W30 oil (it had SAE on it, all they had) and added it. After adding 3 quarts and seeing the oil level not move that much on the dipstick I realized I'm probably reading it wrong. Decided it wasn't sounding strange and the message hadn't come back, so I drove it back home (like 5 miles). Got home and read up on the message and saw that I did multiple dumb things rofl..
TL;DR: had an oil pressure warning and I'm dumb
Anyway, found a repair shop that was open today and drove it in since it seemed to be driving fine and the message hadn't come back. I got there and they decided to start with an oil change and noticed that there was a ton of oil leaking out. Apparently the seal on the filter wasn't good. They cleaned up the leaked oil on the engine, replaced what was in there with synthetic, got an OEM oil filter, and said it should be fine. They also said to come back in 2 weeks to make sure there wasn't any other leaks and I should probably get my front brakes changed at that time (measured at 20%). So here are my questions:
1. Can the low oil pressure warning come on due to simply a lack of oil? Should I still be concerned about sludge or a bad sensor?
2. In the future, if this message comes back on, when it is an issue of sludge does the message stay/continue or does it show once and then turn off? Basically if I see it again and it disappears when I turn the car back on, was it probably a fluke?
3. Anyone know how long I should wait if my front breaks are at 20% (rears are at 60% still)? The repair shop offered to do it for $350 I think and if I recall last time I changed them at the dealer it was even more than that. Figure I should milk them for what they're worth before changing, but the mechanic was saying that 2 weeks would be a good time to change them and if you wait too long you'll damage other parts.
I'm new here btw, so sorry if this is an inappropriately long post. Also I have a 2002 VW Passat 1.8T, 4 cylinder with 140K miles