Toyota 4Runner 1996 3.0 V6 problem mileage : 136,302

I check the fluid levels and antifreeze level, they seem to be at normal values. I am driving my car regularly and recently like about 1-2 days ago. I am starting to hear a Knocking noise that sounds like when I run over a pot hole on the road or a branch of a tree that was twisted and broken off when I turn but there has been no signs of bad performance issues. The sound seems to be coming from the Front passenger side under the fender in the engine compartment. Today when driving the car a funky smell is emitting from the car it smells like burning paper. When I opened the hood a smoke whiteish was coming from the back of the engine near the heater core area but unsure seems like underneath the engine somewhat. And I made a full stop and shut off the car under the car I see anti-freeze dripping but not leaking like something exploded or something snapped. Occurs when I make left turns only.