What kind of regular shop, general repair facility, oil change place, other?
My guesses are that either a leak started someplace that coincides, timewise, with the oil change, that could be unrelated to that service…
Or the oil change was botched and perhaps an oil filter was not tightened, a seal from the old filter was not removed from the engine oil filter flange and that resulted in a stacked double seal that blew a leak. (I have to be cognizant of that on certain GM filters I use.)
Or the filter wasn’t tightened/installed properly…
Or the filter was defective.
I once had a GM car serviced at a GM dealer and had an oil leak shortly thereafter. I investigated and it turned out that the “mechanic” had trapped a piece of a nearby wire harness insulation between filter and filter flange (carelessness). I caught it way before a quart of oil was lost and way before a low oil pressure light illuminated.
Driving with an “oil pressure” (not to be confused with a * “low oil”) warning for even a short period can do catastrophic engine wear/damage. It was good to pull over and stop the engine as you did.
- A couple of my GM cars have both a “low oil pressure” indicator and a “low oil” indicator. The “low oil” indicator which has never activated because I religiously monitor engine oil levels in all my vehicles, (I have tested it while changing my own oil. It has a sensor in the side of the oil pan), but if it did it only means one is approximately a quart low on oil.
If it was me I’d want to know for sure exactly what took place and why (I’d want a look out in the shop). Should the shop own up to botching the oil change service, I’d want some assurance that they’ll cover you on any consequences of that error.
Knowing the age, mileage, previous “health” of your car’s engine is needed here, but you could run it up to another oil change, checking oil frequently to see if it’s consuming and monitoring oil pressure, and then taking a oil sample and sending it off to Blackstone Lab for an analysis.
I used this lab once when considering buying a used car. The test reported the engine was in great health and that the synthetic oil I use could have been run a lot longer, both good to know. You can specify the nature of your test and receive a personal synopsis. 30 bucks can buy lots of peace-of-mind!
[Tests & Price List | Blackstone Laboratories (blackstone-labs.com)]