rburke Posted December 23, 2013 Share Posted December 23, 2013 Hello. I have a '94 L Wagon, manual, 205k miles. Just the other day I noticed that I wasn't feeling much air coming out of my heater vents. I can hear the fan working just fine on all four settings, it just didn't seem to be moving much air at all compared to normal. Today I was looking at it and started it up, and it seems like it comes and goes now. Sometimes it would blow, sometimes not. Mostly not. I just moved and couldn't find my Chilton manual to do some reading in there, but will get it tomorrow from my storage unit. Anyone have ideas? Also noticed today that looks like the water pump is leaking and was low on antifreeze. I wouldn't think a bad water pump would have anything to do with the inside fan issue...? Figured I will replaced the timing belt the same time as the pump since she's due in 13k anyways. Any ideas/tips greatly appreciated! Thanks. Link to comment Share on other sites More sharing options...
Idaho subaru Posted December 23, 2013 Share Posted December 23, 2013 Just to be clear, are you asking about an air volume problem, or a heated air problem? Link to comment Share on other sites More sharing options...
rburke Posted December 23, 2013 Author Share Posted December 23, 2013 Volume. It seemed warm and defrosted the window, but just wasn't pushing much air. Sorry for the confusion. Link to comment Share on other sites More sharing options...
Idaho subaru Posted December 23, 2013 Share Posted December 23, 2013 Mine acts up sometimes because the motor is going out. Try turning the fan on, and reaching under the far right side under the glove box, you should be able to feel the motor, and give it a couple hits. If the motor picks up speed, you're on your way to needing either new brushes or a new motor. I took mine apart a couple years ago, when it stopped working all together, and found a bunch of leaves and debris in it. I ended up cleaning it up, oiling the bearings and putting it back in. Just a week or so ago, it started acting up once in awhile, might have to break down and get a new one. If the motor sounds good, does it have reduced volume on all settings? Or just just one? You may be looking at a failure of one of the mixing doors, but that is beyond what I have had to deal with thus far. Link to comment Share on other sites More sharing options...
rburke Posted December 24, 2013 Author Share Posted December 24, 2013 I did notice when I was messing with it trying to figure out what was wrong, that when it did start to blow more air that I think there was a slight difference in the sound of the motor. When I took the glove box out and was looking under the dash, I peeked in the heater core casing and noticed some leaves in there. Ran out of daylight but planned on vacuuming that out next weekend when I get a chance. I'll be out of town the rest of the week for the holiday. I'll try banging on the motor and see if that does anything. One thing I thought of today...I did notice a little ice on the right (if you are sitting in the passenger seat looking straight ahead at the dash) side of the heater core when I opened the case up. If there was ice on that side of the core, which is the motor side I believe, could that restrict air flow to the ducts? If so, could low coolant (my leaking water pump) be a factor if there wasn't enough hot coolant getting to the heater core? Link to comment Share on other sites More sharing options...
Idaho subaru Posted December 24, 2013 Share Posted December 24, 2013 Probably just dirty. The motor comes out pretty easy, then you can clean it out, put some oil in the bearings and probably get a couple more years out of it. As far as the ice, if you're getting ice on the inside of the car,that could certainly be a problem. You might want to track down the source. If you have a leak getting into the workings of the HVAC, and it freezes, it could certainly block something up or not allow the doors in there to open like they should. As far as low coolant goes, if it gets low enough, it will create an air bubble in the system, that is bad. Air bubbles lead to overheating, which leads to head gasket problems, which leads to lots of money. Inevitably, air bubbles find their way to the heater core because that is the high point of the system. I would suggest doing everything possible to keep your system full. Link to comment Share on other sites More sharing options...
spooln30 Posted December 24, 2013 Share Posted December 24, 2013 Out of curiosity, if you switch the HVAC from defrost to vents and floor does it seem to switch right away and if you push the vent only button does air come from any other outputs? Link to comment Share on other sites More sharing options...
rburke Posted December 24, 2013 Author Share Posted December 24, 2013 Idaho Sub- The ice I saw was on the side of the heater core itself, inside the casing. I didn't know if the freezing air coming into the system from outside could have caused that, haven't seen anything else leaking inside. I do recall last winter I had a few times when I had some ice build up on the bottom of the heater core casing inside the car when the defroster was on for a long time, and then no air would flow. Going to open the motor up this weekend and take a gander. spoioln-I can switch from defrost to bilev to heat to vent and they all switch, and I can feel a little air flowing, but it's just not the full volume it should be. Link to comment Share on other sites More sharing options...
rburke Posted January 9, 2014 Author Share Posted January 9, 2014 So I'm back. Busy holiday season. Finally got the leaky water pump and timing belt all swapped. Fired it up and the heater seemed to work fine. Drove it down to get gas, no problems. Started it up this morning and warmed it up for ~15-20 minutes with the defrost/floor heat on, hopped in and off to work. Within 10 minutes, I noticed the air flow had decreased. The plastic heater core case behind the glove box had ice on on the underside. Tonight after work I drove home with just the heater (BILEV) on and no defrost. Air blew strong and hot as is normal. No ice build up on the heater core casing. I had this problem a couple winters ago, but at the time I was living in an area we never got much snow and only had it happen once a winter so I never bothered to dig deeper. Now where I live, we have real winters. I'm gonna need a functioning defroster at some point. What could be causing the heater core to be getting ice build up like that with defrost on? Link to comment Share on other sites More sharing options...
spooln30 Posted January 9, 2014 Share Posted January 9, 2014 When you switch the HVAC on defrost or the windshield only the AC kicks on so that probably where that frost is coming from. Link to comment Share on other sites More sharing options...
rburke Posted January 11, 2014 Author Share Posted January 11, 2014 I figured that it had to do with the AC when I noticed it only froze when the defrost was on. But why would the heater core be freezing up when the defrost is on? Could the AC refrigerant be leaking possibly? Link to comment Share on other sites More sharing options...
spooln30 Posted January 12, 2014 Share Posted January 12, 2014 The AC evaporator core is on the far right while the heater core is in the middle. If your getting frost on the passenger side its the AC EVAP core and when you switch it on defrost even with the heat on hot the AC kicks in. This helps defrost the windshield faster. Link to comment Share on other sites More sharing options...
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