Cooling System Bleeding?
 

Short story:
Yesterday I changed the coolant in my '97 STS. A little over 3 gallons of old coolant came out by disconnecting tthe lower radiator hose at the rad. I guess it was all what the N* got, as the cooling system capacity is 12.5 quarts, according to the FSM. Put in 3 tubes of BarsLeak, and proceeded to refill thru the pressure tank. All I managed to pour in was a measly two gallons, and it is up to the brim. I did the engine revving with the heater on full blast, and it's not moving...

I was monitoring the temps while driving to work today, and it fluctuated between 194 and 199 F, while before it was more stable between 192 and 196 at about 50-60 F ambient.

I must have poured in the fresh coolant too quickly thus creating one or more huge (one gallon) air pockets which are now trapped somewhere in the N*. My question: Is there a bleeder valve/srew on my '97 N*? The FSM does not say a word about it (or at least I couln't find it). If it does not have an air bleeder, what can I do to to make my Caddy pass gas? Disconnect a heater hose, a hose somewhere else? I'd hate to start from scratch and lose all thet good coolant. [:-]

Any help will be truly appreciated.

RE: Cooling System Bleeding?
 

Work in progress...

This is what I've learned so far from an "oldtimer" in Caddyinfo's Forum:

"The Northstar is self purging. See the 3/8" line that runs from the water pump housing across the inside of the front cam cover to the surge tank? That is the purge line. Assuming that it is not plugged, it will purge any air in the system. Pull the line loose at the surge tank. It should spit coolant at idle and flow will increase with RPM. If there is no flow, locate and clear the obstruction."

I checked, and I do have an unobstructed, clean flowing purge line, so I guess, it's just a matter of time 'til the ol' NS burps up the air trapped in its bowels.