Heater not working properly

Welcome to 2CarPros. And welcome back:

This is an interesting issue because the when you increase the temp, the blend air door actuator is what should react. When you change direction of air flow, there is a different actuator which should respond, the mode door actuator. I think what we should start with is the mode door actuator. What I would like you to do is disconnect it and see if changing the temperature still has an affect on air flow direction. If it does, then we will need to inspect the mode door itself.

The mode actuator is located on the HVAC box under the dash. If you look at the attached picture, I highlighted both the mode door actuator and blend air door (air mix) actuator. You can see they are not close. That is what is causing me confusion.

Regardless, if we find air flow changes after the mode is disconnected, we will have to inspect the door and make sure nothing is loose or disconnected.

Let me know what you find.

Joe

Welcome back:

Happy to help. Let me know what you find. I'm interested in knowing what they find.

Have a good weekend,

Joe

Welcome back:

I can't quite read the RO. Are they replacing the heater core or are they going to flush it? I would try flushing it first.

If it is a flush, you can do it. I attached two pictures below. The first one shows the heater hoses and how they connect to the core under the hood at the fire wall. The second pic is an exploded view of the heater core. I circled the core, and the steel hoses which come through the firewall into the engine compartment.

In pic 1, you will see the hoses disconnected. That it the what you have to do, disconnect the hoses. However, you will need to drain the cooling system partially to prevent coolant from leaking when you remove the hoses. You will still have some loss at the hoses, but it should be minimum.

Once coolant is drained in the radiator (about half way down), remove the hoses. At that point, take your garden hose and spray water through one of the two steel lines. Water will come out the other steel hose. Do this until the water is clear.

Next, reverse flush it. Basically, spray the water into the other tube until it is clean. If water comes out easily and is clean, you're done.

Reconnect the hoses and refill the coolant. Once the coolant is full, turn the heater on high and start the engine. Allow it to warm up. It should bleed the air from the system itself. If it doesn't, let me know.

Please let me know if you have questions or need help. Also, let me know if this takes care of the problem. One more thought, I find it a lot easier if I have a piece of heater hose long enough to push on to one of the steel heater core tubes so I can just spray the water into that. It's easier because first, you aren't trying to reach for the heater core tube with your garden hose, and second, it's rubber so it's easier to spray water into it.

If you decide to get the hose, get about a 3 foot section from any parts store. While at the parts store, see if they have any flush products specifically for heater cores. They will have radiator flush, but I question if that will work for this.

Take care and let me know how it goes.

Joe

Welcome back:

I can't believe they were charging you that much for a flush. Wow! That is something which would be under $100.00 here. I just don't understand things anymore. I had a customer that was quoted $1,400.00 to replace an alternator in a Honda this past week by a well known national chain. I did it for $250.00. I guess one of two things. Either I'm just getting old or I need to raise my prices. LOL It must be age. I couldn't do that to someone.

Take care and feel free to let me know if you need help. Also, let me know if this helps take care of the problem.

Joe

Let me know how it works out for you.

Take care,
Joe

Wow, that looks really clean. And you have no heat? Were you able to bleed the air from the system? Do both heater core hoses get hot when the engine is warmed up and the heater is on high?

As clean as that is, the core most certainly isn't plugged.

Let me know.

Joe

I agree. It is an actuator issue. Let me know what you find with the temperature.

Take care,
Joe

Did you try removing the blend door actuator to confirm that the door is moving?

Hi,

If you remove the actuator you should be able to see if it moves.

Let me know if I can help.

Joe