Did you ever get this figured out Dave ? Could be the leach lines not carrying away the water fast enough. Lint from the washer can partially clog over time.
"Lint from the washer can partially clog over time." I'd rather not go there. Everything still drains, just get the gurgling. It stopped for a couple days, then came back. Maybe there's something living in the drain? If we stagger water use a bit, it's not bad. Almost had the snow melted off the roof enough to get up to check the vent, but got busy, then the snow and cold came back. I've had to roof rake twice since. Still haven't gotten in the crawl. Been busy at my sis-in-laws place. Going over there to meet up with her electrician tomorrow, then going to Alpena on Tues. with my brother to do a little plumbing work at the house we worked on a week or so ago. I'm still trying to get up in the attic, and I did some trim work a couple days ago that's been on the back burner for way too long. Trying to get some of this done now, so I have time in the spring to work on the garden and cut wood. I've asked for longer days, but I'd still crap out after a few hours, so it wouldn't help. Didn't mean to bend your ear.