Yesterday, we had an odd experience with my wife’s 2019 Buick Encore. We’ve had it a little over a month, and it has fewer than 800 miles on the odometer. Here’s what happened:
Temperature was around 20 degrees F. We had just started out from home when my wife noticed excessive smoke/vapor from the exhaust. No CEL illuminated, gauges read normal values. We pulled over and the engine sputtered and stalled. I checked the fluid. Coolant tank full. When I pulled on the oil dipstick, it popped out with a strong whoosh. The crankcase was clearly pressurized. The oil level was full. I then opened the oil filler cap and found some ice. After letting it sit for a few minutes, we returned home, about a mile away, and I re-checked the dip stick. No pressure this time. The car then idled smoothly with no hint of stalling. We then proceeded to go on our merry way to some wineries.
Other pertinent facts: we are in upstate NY (rather cold since we got the car), and my wife drives pretty much only short trips, 15 minutes or less.
My hypothesis: moisture in the oil, not boiled off due to her driving pattern, had frozen in the PCV system somewhere, causing the problem.
Does this sound plausible.