Heater is a constant flow system, so, it doesn't matter where the temp lever is set when you are purging air from the system.

 

How did you purge the air out? Drilling a small hole in the t stat will do it.

 

I was taught to drill thermostat plates early on. No, the one I put in has a jiggle valve. On this I [urged the system by heading up a really steep hill so the heater core would be lower than the top of the radiator. Once I quit hearing gurgling from the heater core, I opened the pressure flap on the radiator cap. That's the little red lever on some caps.

A buddy stopped by when he saw the truck was moved. He mentioned the ticking sound was gone. I told him I took the Schlitz beer can and oil soaked cigarette butts out when I pulled the intake.

 

That works also, Do you have the manufacture and part # of the one with the jiggle valve? How many posts do we see here about trapped air?

 

I really don't know. I just made sure it was NOT a Failsafe unit. Every one of those I've dealt with either were failed when I got to it, or it failed soon after installation.

The thermostat drilling is because of the 1930 Plymouth engines over heating. (Yes, I'm old.) Plymouth's started overheating and the problem was a new thermostat supplier who actually had good quality control. The old units leaked like a sieve. Drilling a 1/64 hole burped the air out.

 

Did some fine tuning on the major tune up today. Some issues from it, mostly debugging the job were,

Coolant drip, tightened clamp

Didn't like to idle cold, old IAC was bad, replaced it

Check engine light kept coming on, code was for purge cycle. Replaced purge valve.

Temperature gauge was reading high. Put new sensor in. Still reads high and went straight to top of gauge reading. Suspect the wire connector is bad. Next trip to the bone yard and I'll cobb a connector out of a wreck.