96 Toyota Avalon No Heat.... Bad Thermostat? info inside

[CJINOHIO03]

Well after replacing the heater core. There is still no heat. I bypass the heater control valve too. By the dash gauge on the car it warms up fine(about halfway on gauge). I thought if the thermostat was bad it would be either stuck open or closed. Which would cause overheating or car wouldnt heat up at all. I know there is coolant getting to the heater core because it was leaking at first where the copper pipes came together at the heater core.

 

Anybody know of a site or link for a factory service manual for this car? Thet Haynes one sucks thanks CJ

[wnaplay1647545503]

Dumb question but you checked all fuses/relays?

[greekdrifter]

go ahead and change the thermostat. Its cheap and pretty easy to do.

 

if your thermostat is almost closing all the way, but not quite, it could keep the overall engine temp lower than normal. It will be letting very cold water into the engine.

 

The gauge may still read close to normal because they are designed to read normal temp throughout a range of temperature, like from 160 to 200 for example. temps are approximate.

[CJINOHIO03]

when u say fuses do you mean if the blower motor is working etc?

[unfunnyryan]

when u say fuses do you mean if the blower motor is working etc?

 

There could be other relays that control things in the background that you aren't noticing. In the mean time, if engine temp isn't getting up to normal due to bad thermostat, put a big piece of cardboard over your radiator.

[CJINOHIO03]

The blower motor is working fine. It warms up to about half way on the gauge. Which is what it always has done. That is why I am not sure if it is the thermostat or not. CJ

[acklac7]

The blower motor is working fine. It warms up to about half way on the gauge. Which is what it always has done. That is why I am not sure if it is the thermostat or not. CJ

 

Maybe the "blend door" on the HVAC system is seized up? Are you getting cold air from the vents when the AC is on?

[ansonivan]

Most modern cars do not have an actual temp gauge, it's a glorified idiot light controlled by an ecu.

 

I would start with the thermostat.

[Dave1647545494]

start with a thermostat if that doesn't do it you may need a water pump the impeller could be worn and not push water fast enough

[Cordell]

If you just replaced the heater core having an air pocket is pretty likely, does it blow warmer if you rev the engine? Have you checked the temp of the heater hoses (with your hands will work)? Possibly a blend door, need to find out some more info to narrow it down.

[Guest 614Streets]

Hook a pressure tester up to it and replace your t stat

[CJINOHIO03]

Does anybody know of a site for factory service manuals? that can be dl etc? how do u check a blend door?

[CJINOHIO03]

Well after reading I dont think this car has a blend door. It has a knob/electronic controls like a lexus to change the settings from hot and cold called an air mixture damper control only. There is no knobs sliders just buttons and a auto setting like a thermostat with a temperature dial. So I dont know what else it can be. I took the water valve(heater control valve) out and bypassed it too.

 

Also what do u have to do make the heater core stop leaking? It has brass pipes that come through the firewall then connect to the heat core but are two pieces (not soldered the heater core) >the only thing that seals it are two rubber o rings and kinda like c clips that go over the two connections but it still drips.