toyota heater not working

[Scottintexas]

1998 Toyota Avalon XLS v6 3L


The heater will only blow outside temperature air.


The engine temperature gauge runs just about mid level.


The coolant reservoir was low. I refilled and drove about 20 minutes, no difference in the temperature and the level in the reservoir stayed the same.


When I move the air temperature control knob from hot to cold the “recirculate air” button changes over so I believe the knob is working.


When I turn the A/C on the air gets noticeably colder so that is working.


When I feel the radiator hoses to and from the engine they are very hot and I can only hold them for a few seconds.


When I feel the heater hoses that go into the firewall at they are only luke warm if at all. It seems as if I can feel liquid movement inside them but it could just be the vibration from the engine.


Shouldn’t the heater hoses be as hot as the radiator hoses?


Any Ideas on how to easily trouble shoot this some more?

 

[latitudeadjuster]

try burping the system. Park on steep hill front uphill or drive front tires on ramps. Open radiator cap, while its cool of course. Start engine and run for a while with heat on high....add coolant as needed. This should burp the system. I have had to do it with my Armada a couple times.

Let it run for a good while with the cap open.

 

[itsdgm]

I agree with @latitudeadjuster. it could be air in the lines. By the way, adding coolant to the overflow won't add coolant into the system until it cools back down and draws it in. So it would be better to check it at the radiator anyway (when it cools down). If the radiator was full, your issue could be with the valve/switching mechanism that opens up the flow into the heater core. Could be the switch (heat control setting) or the actuator that opens it up.

 

[latitudeadjuster]

Yes, You will have plenty of overfill from the burping process so adding to the reserve will not help but may overflow.

 

[Scottintexas]

update,
I didn't have time to try to burp it today since it's always hot, I did however have a few minutes and was able to disconnect the valve on the feed line at the firewall, It would not move no matter what setting I tried on the dash. I looked at a two other toyotas, an 05 and 08 and neither of them had this valve (at least on the engine side of the firewall).

After I took the control arm off and moved it to "open" both the feed and return heater hoses became as hot as the radiator hoses so I am assuming the heater core is not getting hot but will check that when I open everything up next time.

The air blowing remained the same outside air temperature though. I now believe the problem may be the diversion door not opening allowing air to blow over the heater core.

 

[itsdgm]

I'm pretty sure air always flows over the heater core. But if the valve doesn't open up and let hot water in, the air stays cold. Sounds like your valve isn't opening up properly.

 

[itsdgm]

Here's a few links that might help.

http://www.fixya.com/cars/t16274560-heater_blowing_cold_air

http://www.fixya.com/cars/t22106520-1999_toyota_avalon_heater_only_blows

 

[Scottintexas]

thanks dennis for the input,
I forgot to add the picture of the valve I disconnected and manually opened to get the heater hoses hot, here it is while still connected,

 

[Scottintexas]

I decided to take it to the mechanic. The motor that drives that cable was to far under the dash for me to mess with and I wasn't sure if it also controlled the blend door.

$450. and no more of my time or laying sideways over the drivers seat it's fixed. They replaced the control panel and then found out that motor wasn't working correctly and replaced it also,
anyways, glad to have it done! thanks for the suggestions

 

[Big Shasta]

I usually do everything myself but you did the right thing, Some things just aren't worth fighting with.

 

[itsdgm]

Glad you got it fixed. Some of those heater issues are hurried deep into the dash. $450 isn't too bad. It beats the sore back and shoulders that probably would've come with doing it yourself