(06 Tacoma 4wd 2.7l 230k) recently did a full flush ran about 6 gallons of distilled water through it until it came out clear, took our thermostat for first 2 flushes made sure everything was drained before I filled with coolant. It’s supposed to take roughly 2.5 gallons I couldn’t even get 1.5 back in the system. Idled it with the cap open and coolant bubbler funnel installed for over an hour. Drove it around checked it a few days later. Reservoir went from full to low, re burped for half hour refilled reservoir to full. Still hearing gargling in the system like there’s air trapped. Heat blows HOT, truck doesn’t overheat whatsoever. Any tips or tricks on how to completely purge system of all air and get remaining amount of pre indicated coolant in the system? Dealership just says squeeze the lines/ not very helpful at all.