I have a 3 year old home. My upstairs guest room toilet has been giving me trouble since day one. Occasionally, I would come home and find a horrible odor from the toilet and find foul water in the bowl. No one used this for weeks.
I continue to get slow drainage from the bowl. I rarely get a full suction to emtpy the toilet after each flush. I have no issues with the sink or shower in the room draining.
Now comes the crazy part...about 1-2 minutes after I flush the toilet, a loud, audible vibration occurs near the toilet and lasts for 30 seconds.
My initial thought is that the toilet isn't vented properly, but would that account for the trap being sucked out on a windy day? I would assume there would need to be a connected vent for this to occur. Also on windy days, I get sloshing of the water in the bowl. Is it from the clean out in front of my home? I don't know where to begin.
Any help is much appreciated.