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-   -   Manual Heat/AC - No heat passenger side = bad heater core? (http://legacygt.com/forums/showthread.php?t=129814)

Hatepylons 01-27-2010 10:06 AM

Manual Heat/AC - No heat passenger side = bad heater core?
 
Stats: 2006 Outback Wagon, Manual Heat/AC, just completed 60K service including coolant change.

Not sure what to make of this one. The heat on the passenger side has vanished, gone, completely. Air flows, but it is damn cold. The air velocity is equal on the driver's side and passenger side.

When the temp is set on max, if I change from recirculate to fresh air, it gets a touch warmer on the passenger side vents, but it's negligible. Since it's so cold out, I cannot tell if there is any temp change with the A/C on going from hot/cold.

So, realistically, if I am looking at the parts breakdown correctly, the air mix door is one piece, correct? The only thing that leaves me with is a blocked heater core.... which is just staggering considering the mileage. The fact that I am getting almost zero heat on one side, and sweltering hot on the driver's side makes me want to believe something else.

I do not have any gurgling from the dash indicating air in the coolant system either. Am I missing something, or is my heater core most likely blocked?

http://i115.photobucket.com/albums/n.../HeaterBox.jpg

GTTuner 01-27-2010 10:20 AM

You have single or dual zone heater in front?

Hatepylons 01-27-2010 10:29 AM

Single zone, 100% Manual.

GTTuner 01-27-2010 10:44 AM

IDK, a blocked core I would assume you would get no heat at all. I'd have the dealer bleed the cooling system again.

ktmrider 01-27-2010 12:41 PM

Like mentioned the core is common to both sides so I doubt it's that.
There does appear to be a RH and LH heating system despite the non-dual zone controls ( cheaper than swapping HVAC units maybe ).
Have you checked whether heat blows in different modes? Foot, vent, defrost, etc.
Hope you find it, too dang cold this time o year!

GTTuner 01-27-2010 12:43 PM

Quote:

Originally Posted by ktmrider (Post 2803435)
Like mentioned the core is common to both sides so I doubt it's that.
There does appear to be a RH and LH heating system despite the non-dual zone controls ( cheaper than swapping HVAC units maybe ).
Have you checked whether heat blows in different modes? Foot, vent, defrost, etc.
Hope you find it, too dang cold this time o year!


Good point mentioned here; Do you have the same problem in all modes?

captainhook 01-27-2010 02:31 PM

Quote:

Originally Posted by Hatepylons (Post 2803153)
Not sure what to make of this one. The heat on the passenger side has vanished, gone, completely. Air flows, but it is damn cold. The air velocity is equal on the driver's side and passenger side.

When the temp is set on max, if I change from recirculate to fresh air, it gets a touch warmer on the passenger side vents, but it's negligible. Since it's so cold out, I cannot tell if there is any temp change with the A/C on going from hot/cold.

SAME EXACT DEAL with my car! I took it in last week for a warranty claim on it and when I got there the tech tells me, "oh, that's a common problem." So I figured cool, they'll fix it no problem . . . well I get a call a few hours later saying that they think there is a blockage in the heater core and expect ME to pay $100 for them to flush it to see if that really is the problem. I said that was bullshit because the AC clearly falls under the bumper to bumper warranty, and I wasn't paying a dime. Well they discharged the car and refused to fix the problem, so now I'm stuck calling SOA over a "common problem." :mad:

Hatepylons 01-27-2010 03:15 PM

Quote:

Originally Posted by ktmrider (Post 2803435)
Have you checked whether heat blows in different modes? Foot, vent, defrost, etc.

Been there, done that, got the T-Shirt. Well, in this case, the jacket. Blows cold, no change in outlet temp on the passenger side regardless of vent outlet position. (Floor, defrost, etc).

Hatepylons 01-27-2010 03:23 PM

Quote:

Originally Posted by captainhook (Post 2803622)
SAME EXACT DEAL with my car! ... so now I'm stuck calling SOA over a "common problem." :mad:

I ended up filing a complaint today with Subaru NA and opened a case file. My local dealership is great, but they've never encountered it before. I have some suspicions about what leads to the clogs, including the non-tight fit of the overflow hose into the overflow tank letting debris in the system.......

Hatepylons 01-27-2010 03:27 PM

Quote:

Originally Posted by GTTuner (Post 2803206)
IDK, a blocked core I would assume you would get no heat at all. I'd have the dealer bleed the cooling system again.

I 100% agree with your above statement. The only thing that makes sense is the core was designed like a radiator with an upper and lower tank allowing multiple paths through the core. Since I have not found any images of what the core looks like, I cannot confirm.

Going to reverse flush it tonight, see what comes out. Hopefully a hairball. :eek:

Hatepylons 01-28-2010 07:57 AM

No magic hairball.....
 
Quote:

Originally Posted by Hatepylons (Post 2803721)
Going to reverse flush it tonight, see what comes out. Hopefully a hairball. :eek:

So I reverse flushed the core last night using a clear pvc line on the drain to see if any sediment came out and cling to the inside of the tube. But nada. :spin:

I do now have a "smidgen" more heat on the passenger side now as a result of my efforts, but definitely not enough to see the problem is solved. I only flushed 15 gallons through it, perhaps I'll flush it all night with fruitless hope.

pillboy 01-28-2010 11:48 AM

When you change the temperature setting, does the temp of the air on the driver's side change in relation to the control? Makes no sense that the core could be at fault if there is hot air on the driver's side. Has to be something in the duct work or the doors that route the air flow.

Hatepylons 01-28-2010 12:00 PM

Quote:

Originally Posted by pillboy (Post 2804940)
When you change the temperature setting, does the temp of the air on the driver's side change in relation to the control? Makes no sense that the core could be at fault if there is hot air on the driver's side. Has to be something in the duct work or the doors that route the air flow.

Yes, the heat changes on the driver's side when I adjust the temp control. I could buy into something in the ductwork if I had a reduced flow on the passenger vents, which I don't. Apparently there was an article in the Feb 2008 Subaru "Technotes" newsletter that talked about sediment blocking up the core, specifically after a coolant flush/change. :spin:

I wish I could see a design of the core so I could better understand the fluid path through it. The only thing that makes sense (assuming it is partially blocked) is that the core was designed as a radiator with top/bottom tanks, allowing the coolant to have multiple paths within the core.

Keep in mind that on this manual A/C Box the air mix door is one piece, traversing both sides of the box. If the air mix door was jammed in anyway, then I'd have equal symptoms in both vents.

PATroutChaser 01-28-2010 04:05 PM

Same Issue
 
I too have the same issue. Perfect heat on all settings and levels on drivers side. The passenger side remains COLD in all setting and levels. The defrost splits dead-nuts hot/cold for drivers and passenger sides...It's almost like there is a door that routes air from heater core to driver and passenger sides and is stuck shut. I call my dealer and they too have never heard of the problem...this one's driving me crazy...

Mine is manual operation as well....

Derrick

Hatepylons 01-28-2010 09:02 PM

Quote:

Originally Posted by PATroutChaser (Post 2805367)
I too have the same issue. Perfect heat on all settings and levels on drivers side. The passenger side remains COLD in all setting and levels. The defrost splits dead-nuts hot/cold for drivers and passenger sides...It's almost like there is a door that routes air from heater core to driver and passenger sides and is stuck shut. I call my dealer and they too have never heard of the problem...this one's driving me crazy...

Mine is manual operation as well....

Derrick

That's exactly my symptoms too. Now, since the flush, I've noticed that I do have more heat than I did. Here's something I didn't notice before. With the mode on fresh air, I have less airflow on the passenger side when the temp is max hot. On cold the flow is even.

When I turn on recirc, both sides blow even on hot, but when I turn to cold the passenger side has less??? WTF. I clearly have something else going on, maybe in addition to the heater core? IDK. I'm just going to have to stop theorizing and pull it apart.


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