Coolant flowing back into reservoir while burping COT
What the titles says... I heard some gurgling while driving the other day so i figured id check the COT for air. I elevated the car on ramps on a sloped driveway so definitely had enough inclination. I added about two quarts to the COT bleeder hole before I realized it was filling up the reservoir. Reservoir cap was on tight, no coolant leaks or wet spots anywhere else on the car/ground What did I do wrong or where Im I relieving pressure to allow coolant to flow back? Im thinking start with new radiator cap since its original. Thoughts?
2004 Silver Birch w/moonroof. "Isabelle"
Eaton swapped summer/fall 2015 with all the gooddies, tune by the one-and-only Marty-O +2psi pulley, Steigemeyer stage 6 port, SWLT, custom ss exhaust, Borla ProXS, Addco sway bars, TCE s/s brake hoses, Hawk HPS pads, Zack big brak kit, J-mod, battery in trunk, full custom audio (never used, blower whine sounds better)
To do list:
HID headlights, LED interior/exterior, courtesy "3-flash" turn signals, widen wheels, rear deck wing, marauder stencil on cmhsl? bumper cover inserts? deck lid, steering whee, hood liner godshead, more power!