Heater Core or Climate control problem?

[mweedman]

Hi folks,
This seems like a decent site for back yard garage DIY Avalon owners, like myself. I searched this site as best I cold , but could not find anything definate. Please forgive me if this topic has already been covered and point me to it.

Otherwise, here is the problem.
I noticed last winter that the although I placed the climate control on like 80 degrees, on winter mornings on my way to/from work, it never really got very warm in the car. (probably like 65 degrees). Nor did the air coming out of the vents feel particularly warm.
So I made a mental note myself to check out the heater core when it got warm. I wasn't terribly concerned yet because after all, I could survive 65 in order to make it to the summer to work when cracking knuckles on a block does not hurt as much.

Anyway, as I have driven through this very hot midwest summer I have noticed that the temperature control is off for the A/C as well as the heat , and in the same direction.
i.e. When I put the climate control on 85 degrees in the winter, I get 65-70 degree temperature in the cabin. Likewise, when I put the climate control on 80 degrees in the summer, I get a cabin temperature of probably 70 degrees.

Anybody hear of anything like this?
I'd rather not replace the heater core , if this might point to something easier, maybe cheaper to fix.

Thanks for any help any of you can give!
Mark

[edison3373]

Hi am an retired auto service manager. Your problem sounds like the themostatic sensor is out of wack. I am not familuar with this setup so I do not know if it is adjustable or must be replaced?

Frank

[kldavis]

Hey mweedman, I also have a 2000 and my driver side will only blow cold and the passenger side works fine. Are both your driver and passenger giving you trouble? I want to find out if the control knob itself could be bad of if its more involved.

[mweedman]

That's a good question KLDAVIS.
Un fortunately , I don't have the answer, but I beleive that in my case, it's the whole thing. I am beginning to beleive that maybe I just have a heater core problem. I'll try to check and find out if it is different for one side vs the other.

[mweedman]

Edison, that was my thought, but I was looking for some insight into that area. Perhaps (not with my luck), that would be easier and cheaper to replace than a heater core. I have replaced 1 heater core in my life and from what I hear I got lucky. It was on a '77 olds and it was on the firewall, in the engine compartment, not in the dash! It was one of the easiest things I have ever done to a car.

[kldavis]

Hey mweedman, I assume your car is the xls model, so i know it is a little different from mine. I would take a look at your damper/blend door on the drivers side. If you pull the carpet down near the accelerator and on back towards the seat(just tuck it down), you can get a good look at the blend door which regulates the hot and cold air. I had to lay on the back in the floor board to see it. Have the vehicle running and change the temp while you watch the damper door. You will see a white arm and slide and a cable attached. My car had a cable, yours may be different, however you want to make sure your damper door will move to full heat and cold. My problem was simple, the cable was disconnected and therefore I only had cold air. I connected the cable and now it works. I know you have electronic controls and most likey other components but hopefully this will rule out any climate control problems. Also, the heater core lines run in this area--I noticed them to be very hot. I'm not a mechanic but if the lines are hot, you would think the heater core is working properly. Hope this helps.Ken

[mweedman]

Thanks for the useful advice Ken.
That is the best advice I can get....(the cheap kind)!!
I'll try to take a look tonight or tomorrow when I get home from work.

Mark