"Gurgling" Noise in Dash

[jcslocum]

There's no control valve on the core??

[Meir]

Originally Posted by jcslocum

There's no control valve on the core??

No. there is not.
The hot and cold air coming out of the vents, are controlled by flaps inside the air box.
For the same reason, vehicles that have foam coming out of the vents, usually don't have heat.