I have the waterfall sound. Don't think is a BHG

[mrnickleye]

Originally Posted by btwilson86

Turning the heater on allows the coolant to travel through the heater core, so you DO need to have it on to burp the system. The reason we have to burp our cars is because the heater core just happens to be the highest point in the Supra's cooling system, higher than the radiator cap. This allows all the air trapped in the system to collect in the core. When you correctly bur the car, the angle it sits at allows the radiator cap to become the highest point thus allowing the air (very slowly, so it'll take quite some time) to travel to the cap and exit the system. You will most likely have to burp the system many times to get *most* of the air out.

All true except the "heater must be on" part. If the system is still setup in the original factory condition, (mine is not), then The coolant ALWAYS flows through the core UNLESS the temp is set to 65*. The vacuum operated coolant valve under the hood on the firewall in front of passenger is what shuts on/off coolant to core.
Normally vacuum is always applied threw the VSV.

VSV's go bad. You can just by-pass it, and hook vacuum straight to the coolant valve.