2013 No heat

[Highway_livin]

I've checked other threads, can't seem to figure this out. First, appreciate any help I can get.

2013 1500 5.7 HEMI. Had an issue where I was getting heat on passenger side, cold on driver. Sent it to a shop. They flushed the system 3 times, said it was better than when I brought it there. Drive home in -23°C weather, froze me out for a 14 hour drive with no heat on either side. Just now cold air. Me and a buddy pulled the dash down to the firewall and replaced heater core with a new one. Got the air out of the system. Heat worked for maybe a day.

Today, 15 hour drive back to work, weird situation I've never seen before. It blows cold, both sides, while driving. Rpms 1500 and below it's cold. If I park and kick it up to 1500+ rpms, I got heat. Any idea why?

Things we know so far:
-Thermostat is opening, the line was empty, after a few minutes, felt full.
-I can turn temp control from hot to cold and vice versa and it switches.
-tried the HVAC reset procedure, lights don't flash on the recirc button.
-The shop that first worked on it, put an inline filter in to catch debris/buildup, etc. Filter looks clean.
-Both core hoses, before and after filter, up to the firewall, are getting hot.

Readings according to gauges, while idling:
-outside temp currently -1°C
-coolant 92°C
-Trans 66°
-Oil 92°

When driving
Coolant 91-97° roughly
Trans 70°
Oil usually about 95-98°

I'm lost, not sure where to look anymore. No clicking in the dash (indicating stuck actuator).

Picture enclosed so you can see the dash setup I have.

 

[jws123]

Sounds like air in the system/low coolant I would bleed the system again it can be a pain sometimes to get all air out of the heater cores on these. Let it run cap off up to operating temp sometimes I squeeze on the heater core lines with gloves.. forces the air out ul see a lot of bubbles come up.

 

[Highway_livin]

I topped off the coolant but the only way I can think to get the air out is leaving the cap off while it idles, unless you know another way, I'd be happy to try

 

[Wallyb4]

On some of the thermostat housings there is a bleeder valve on them. You can use that to get all of the air out of the system.

 

[Highway_livin]

Ok, awesome. I didnt know this. Thank you very much, I'll give that a try.

 

[GTyankee]

HEMI Engines have 2 ways to bleed the air off, engine shut off.

Both bleeders are part of the water pump

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