A/C does not work, warm air blows on cold setting

SHADOWFIGURE

MEMBER
2005 SUBARU OUTBACK
186,000 MILES

When I have the thermostat set to cold/cool for non-mixed ambient outside air to be blown at any speed, it blows warm air that smells like the engine bay.
This remains true under all driving conditions until I reach highway speed. Then I get normal outside temperature air blowing through.
Why is this, how can I fix it?
I live in a cold state, so the normal outside air is my air conditioning.
Heat works just fine, and the variable mixing works fine.
Thanks

2 Replies

KASEKENNY

MECHANIC
18,907 POSTS

The reason it is warm and smells like the engine bay is because the HVAC system is pulling the air out of the engine bay and the engine is hot and smells so it heats the air and gives it that smell.

So this means we need to find out why the system is pulling it from the engine and not the fresh air vent in the cowl.

This could be that the cowl is clogged and it just pulling the air from where ever it can get it.

I would check the cowl (circled in second attachment below) and then we are going to have to check the actuator that is shown as well.

Let us know what you find with this and we can go from there. Thanks

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Friday, May 7th, 2021 AT 7:12 PM

JACOBANDNICKOLAS

MECHANIC
109,724 POSTS

Hi,

Is this a new problem? I ask because it isn't uncommon for a short cool-down period when the vent is selected.

Also, have you replaced the cabin air filter? That could be causing issues if it is very dirty.

First, if you haven't replaced the filter, check it. Next, I attached a pic below (pic 1) showing the fresh air door actuator. This could be sticking as well. You may need to remove and inspect its operation.

Starting with pic 2, I included the directions for replacing the cabin air filter. It's behind the glove box.

Let me know what you find or if you have other questions.

Take care,

Joe

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