Drivers side heat problem

I posted the following in the 2.0 gen section and no one replied. Sawa similar post here and thought this may help him and maybe get me an answer. I have a new heater core coming tomorrow and will pull the dash this weekend. Convinced my core is half blocked.

So, having heat issues on drivers side. Pass side is great. On drivers side, I get pretty much cold air through the DS floor vent, luke warm air (almost as warm as Pass side, but still cooler) through the rt DS dash vent and cold air through the left DS dash vent. Haven't really played with defrost yet. The above is with the mode in floor mode. If I go to dash mode, airflow is stronger (believe that is normal based on searching here), but same warm on rt vent and cold on left vent. If I move the blend knob from full red to full blue, the temps of everytrhing on the DS gets cooler, even the cold on the left dash vent. Therefore, I ruled out the DS blend servo.

I have what I believe is the non auto system. It is all servo based, yet does not have an auto setting. Just a temp knob (blue to red) and a mode knob.

Yesterday spent the whole day trying to flush the heater core. Hours of flushing in both directions with various different chemicals. Still getting black flakes and specks, but it takes a LONGGGG time to get them to come out. Still the same problem. Convincedd that there is still more in there, but not positive that half of the core is blocked. Still unsure what the black stuff is. It is not rubber. either corrosion or paint. You can make it break down with your fingers, so not likelly plastic.

Finally gave up and decided the dash has to come out to replace the heater core. I want to be sure that I am not getting a head fake here and this is really an issue with the servos or broken arm on a door. What makes me wonder is that I get cold air through the floor vent, yet one dash vent is warm and the other cold. Because I have not seen the inside of these units, I can't determine what that means.

I should note that the PO was an absolute hack. Everything he touched was wrong, including taking apart the trans case actuators and reassembling incorrectly, installing carrier bearing upside down, etc. Therefore can't rule out the possibility that the DS servo assy was removed and reinstalled incorrectly.

Would really appreciate some guidance from someone who has been through this.

Thanks in advance for any help.

Larry

 

Broken actuator in the HVAC behind the dash. The one that controls either heat or side to side. It’s sucks. Had similar issues. Had tor replace the HVaC box. Was a $2500 bill. They have to take out dash to replace

 

My follow up here

https://www.tundras.com/threads/drivers-side-heat-problem-need-expert-opinion.151575/

it was a partially plugged heater core in my case. Also requires removal of the dash andhvac box. Replaced the evaporator and txv while in there just in case. Only $150 in my case.