Yea, I have a slight knock caused by
Up until a month ago, I never knew what the sound was, a neighbor mechanic says its knock, but I'm not very sure thats true because its very slight, more like a deep clicking sound coming from the plenum area, thats why I'm thinking more valve adjustment. Only happens at about ~500rpm when I gas then goes away when I drive. Comes back when the car comes to a stop. IIRC it goes away after the car warms up. When you check, try to pinpoint exactly from where its coming from, thats why its best to rev by hand with the TB, the only way to pinpoint exactly.