Stumped! No Heat On Passenger Side, Help!!!

[sinuuar]

Oh man, 6 years I've had my 04 XRS trix and no issues, now the weather is well below freezing (-17'C) and i have barely enough heat on the passengerside to clear the windows let alone keep someone comfortable. The far left vent is the hottest very close to being uncomfortable, then warm, cold and finally f-ing freezing. It's also the same when i put it on the floor vents the driver side is hot and the passenger side just blows cold. I also noticed the same when i try to defrost the windshield hottest on the driver side and cold on the far right.(never check the rear floor vents)I did a search and I only found a couple of post regarding this issue (coolant burping while driver side is jacked up and diverter flap)I really need the car fixed and ready for the holiday season.Things i looked into:coolant level full and burped with car jack from multiply angles and while on ramps.thermostat original but seems good, the car heats up quickly and stays where it should be.recirc flap working, motor/gears confirmed no issues (cycled it a few times)hot/cold and diverter flap checked ( i unhooked both cables and stroke it thru the full range) no issues works perfectly.Cabin air filter good (took out it just to make sure there's no issue)Heater motor good, works on all 4 speeds excellent airflow thru the vents.coolant flush done twice since newhoses original, doesn't feel like theres any soft spots.Pulled out the head unit i put in the summer to see if i did something wrong when i installed it.It's too cold from me to back flush the heater core (working outside on the street) far too cold to drag out a water hose................Anyone ever have a problem like this? The A/C worked fine all summer.You guys think there's a problem with the heater core? I don't think anything got in the hvac, it's a daily driver and i always had a cabin filter installed.........how hard is it to get to the heater core? with a lack of water hose and freezing the core solid I'm wondering if i can pull it and flush it out or evenreplace the damn thing and hoses/thermostat. It's gonna be alot of work for me i'm hoping there's a easy answer.......Thanks, happy holidays.

[joatmon]

Welcome to genvibeIf there's air flow out the cold vents then it seems like there no obstruction in the ducts, enigne temp and drivers vents work fine so it's not a thermostat issue. From what you said you already checked out, it sounds like it is probably some issue with the heater core, either a trapped air bubble or another kind of blockage. Here's a picture of a Matrix heater core, with an inset showing the location/orientation of the heater core in the HVAC box inside the car.The way it's built there's a header on each side, and multiple parallel passages from inlet to outlet. When it's installed in the car, the driver's side is the one with the hose connections. It's behaving as if there's no flow through the passages farthest away from the hose connections. It seems as if the air would get mixed in the ductwork where there wouldn't be such a marked left/right separation, but that seems to be about the only thing left to explain your situation.You can see the pipes are bent to swap top to bottom orientation between the core and the hose end of the pipes. When installed on the car, the lowest (closest to ground) edge of the heater is connected to he higher of the hose connections at the firewall under the hood, and this is the outlet. The highest edge of the core, and the lower of the pipes under the hood is the inlet. While I've never swapped a heater core in a Vibe or Matrix, I have in older cars, and in those cars it was truly a job to fear. Maybe it's easier on these cars, but if you're hesitant to run a hose out to the car to backflush the core, then you probably don't want to be out there doing a heater core swap. If it were my car, I might try just swapping the hoses at the heater core pipe ends under the hood at the firewall. That "should" be about the same as doing a backflush. One problem would be that in swapping the hoses, you'll end up putting air back into the heater hoses, and it might need to be burped or backflushed again. But if that works, you might just leave it that way, I don't know if it really matters.Of course, I could be wrong, and if you do that and the car explodes, don't blame me

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[sinuuar]

Thanks, I got heat now. I'm extremely happy, blows hot through all the vents now.The car was warmed up because i had a errand to run and had no heat on the passenger side (same as before), swap the hoses and topped up the rad and was waiting inside the car while she was warming up (car was on level ground). I immediately heard gurgling which i never heard the times before and had heat on all 4 vents instantly.By using your description and drawings I think the hoses were swapped by accident the last time i had it flushed (summer not by me). The coolant would fill from the upper end and immediately drain down allowing heat only on the left side and air to be trapped since it wasn't flowing from bottom to top.Or i could be completely wrong and it was plugged solid and i have all these little bits of junk circulating thru my cooling system waiting to foul something else up........... On hindsight i probably could had grabbed a few 2 liter bottles of hot water and rigged up something to flush it by hand and had the hoses reinstalled in no time since they were pretty easy to get at and not worry about the core freezing up.I have heat and I have you to thanks First time in weeks i was able to turn down the heat setting and not switch back and forth on the recirc.

[the_sarge]

Glad to hear you have heat! That's what's great about this forum...good info from people willing to help.

[joatmon]

That's pretty cool that it's fixed.Now that you here, post some pix of that trix