I just poured a quart of Valvoline 10W-40 into a car engine and when the bottle was almost empty I saw what looked like a slug go into the funnel and on into the engine. I stopped pouring and looked into the bottle and in the bottom the the bottle the oil looked like it had gelled. I have had this oil for an estimated 15-20 years out in my tractor shed. In the past I have seen 2 stroke oil gel in the bottom of the bottle after several years, but I did not know it would happen to motor oil. Anyone ever seen this?