RRS heater issues

[pinkytoe69]

I have an issue with weak heat on the driver's side. Passenger side is very hot.

Center driver-side vent and footwell are on the warm-ish side of lukewarm. The window side vent is a little bit better. The actual airflow from these vents seems lower than the passenger side as well. The window vent on the driver's side seems to have a little bit better flow.

The driver's side heat is improved upon from last year when I had virtually no heat.

A year ago I poured CLR in the heater core and let that sit overnight, then flushed it both directions with hot water and pressurized air. Got some white sediment out...Maybe a 2-4 tablespoons.

Today I finally pulled some codes on the HVAC system and got this:



Am I replacing some blend door actuators here?

 

[pinkytoe69]

Reading that the 74 to 77 is common for a weak battery and a very cold start.

It's 4° here right now..

 

[discostew]

All those codes don’t have anything to do with your problem. You have a restricted heater core. I know you think I’m crazy but it’s true.
The first one I saw was back in 09. Technical assistance was no help and had me put a complete heater box in one. So I took that box apart and figured out that the heater core had a bunch of sludge building up in the drivers side of the heater core.
I know you’re going to ask if you can flush it out. I have had no luck doing that. But I suppose it’s possible.

 

[pinkytoe69]

All those codes don’t have anything to do with your problem. You have a restricted heater core. I know you think I’m crazy but it’s true.

No, I believe it. I read that there's a 99% chance these symptoms are heater core, but the codes teased me for a second.

The fact that I went from no heat to lukewarm heat does give me some hope that doing another CLR treatment will give me a little more heat as well.

I have a radiator flush but I don't know if that's too powerful to just leave sitting in the heater core for a little while...

 

[discostew]

Because of the way the crap builds up at the end of the core it’s really hard to get the flushing to carry it out. I’ve thought about getting a small hose to the bottom of the sludge and blowing air into it while flushing. Just never figured it out.

 

[discostew]

No, I believe it. I read that there's a 99% chance these symptoms are heater core, but the codes teased me for a second.

The fact that I went from no heat to lukewarm heat does give me some hope that doing another CLR treatment will give me a little more heat as well.

I have a radiator flush but I don't know if that's too powerful to just leave sitting in the heater core for a little while...

I think you’re going to end up replacing the core to fix it. You can cheat a little, it’s a little bit of hacking. I take the pipes off the new core and leave the original pipes in the vehicle. You have to be very careful how you bend one of them out of the way cause it’s going to need to hook back up without binding. The other pipe will flip up out of your way without bending. Once the pipes are out of your way the core will slide out toward the passenger side.

 

[pinkytoe69]

I think you’re going to end up replacing the core to fix it. You can cheat a little, it’s a little bit of hacking. I take the pipes off the new core and leave the original pipes in the vehicle. You have to be very careful how you bend one of them out of the way cause it’s going to need to hook back up without binding. The other pipe will flip up out of your way without bending. Once the pipes are out of your way the core will slide out toward the passenger side.

Yeah I saw a land Rover Dubai or something dealership video where they did that-ish.

Their pipes were already "2 piece" tho

 

[pinkytoe69]

Because of the way the crap builds up at the end of the core it’s really hard to get the flushing to carry it out. I’ve thought about getting a small hose to the bottom of the sludge and blowing air into it while flushing. Just never figured it out.

This was my Macguyver contraption that got me back to lukewarm. The open end of the Y is connected to hot water from my basement.

How much psi can you put thru the core? I only went up to 30.

Also, which is the in/out?

 

[discostew]

For in and out just grab them. I’m will be hotter. 30 psi is a lot. Figure the system is designed to run at 15 psi.
Early trucks did have pipes that separated. There was a clamp that held it all together. The new ones you have to bend some tabs to unclamp and clamp it back on. I use a roll pin punch and a small hammer to bend the tabs back over the pipes.
The glove box has to come out and I take the center stack support housing out. That’s the small piece of dash that’s not dash and not center console. Where your audio and climate controls live.