I like to understand how things work and Why?

Northstar 4.6 in 94 Deville Concours has a purge line from top of coolant Surge Tank that goes under the engine valley cover and terminates at base of the throttle body. I understand this line is the air breather line to allow air to escape from coolant system.

Why does this line run to the throttle body? Does it terminate at the throttle body? Wouldn't the line have to reconnect with the cooling system to allow air to (escape) purge?

I talked to some knowlegeable people on this and they were vague?

On this subject I suddenly feel as dumb as a box of rocks.

Please help

It doesn't run to the TB. It runs to the water pump housing I believe. Also, keep in mind that the TB does have coolant flowing though it to warm it up in cold weather operations.

It DOES run to the throttle body. I'm rebuilding a Northstar as we speak, and I hooked up that line last night. As Ranger said, there is coolant curculating thru the throttle body housing. This is the highest point in the cooling system.
One of the coolant pipes at the bottom of the surge tank runs behind the engine to the base of the thermostat housing. That's how coolant gets from the fill tank (surge) into the engine.

It DOES run to the throttle body. I'm rebuilding a Northstar as we speak, and I hooked up that line last night. As Ranger said, there is coolant curculating thru the throttle body housing. This is the highest point in the cooling system.
One of the coolant pipes at the bottom of the surge tank runs behind the engine to the base of the thermostat housing. That's how coolant gets from the fill tank (surge) into the engine.
Thanks for the correction Harry.

Beginning to dimly see the picture

Purge line from SURGE tank does go to base of throttle body. What happens next?

I am working on the belief that the purge line should only have AIR in it. It's sole function is to REMOVE trapped air from cooling system to prevent air pockets that may cause thermostat to FRY itself (deteriorate the wax motor) if overboil starts and allow engine damage to propagate. Am I correct?

The throttle body is not the water pump so where and how is that connection made?

Any opinions expressed by my self are purely anecdotal , am not an "x spurt"

please help