On my way back from Utah after 6 days of off road adventure, my heater stopped working. Turning on Auto and turning up the temp only resulted in cold air blowing. Using defrost does not change the direction of air from the forward vents to the above-dash vents. Any thoughts about what happened? LC2018.
No warm air from vents into cabin
- Thread starter carlson7472
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Random thought. Have you checked your coolant level?
It may have to do with the cool box. If the cool box is on then you’ll be unable to turn off the AC. Unsure about the direction of vents though.
- Thread starter
- #4
The cool box is not on.
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- #5
The coolant level is low.
Markuson
SILVER Star
Did you mean refrigerant?
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- #7
The coolant in the white plastic reservoir is low. It's not on L but near it. I am not sure about the refrigerant.
Markuson
SILVER Star
Somewhere between the two coolant lines is normal. It fluctuates during use
Just trying to figure why it was suggested that that would prevent heating the interior. It shouldn’t AFAIK…
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- #9
I checked the coolant when the car was warmed up giving me a higher reading on the reservoir. If the coolant is low or absent when cold then there is not enough coolant to move through the heater core.
Markuson
SILVER Star
Ah. OK.
But wow. I would think it would need to be much lower than the overflow box lines to cause that…but I don’t know.
nwfl4runner
GOLD Star
Have you topped it off and tried?
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- #12
I just topped it off and tried and still no heat. Hmmm. Need a next step.
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Markuson
SILVER Star
have you tried setting your heat all the way to high, which is above 85°? That should override whatever your interior temperature readings are and just go full blast with heat. If it comes on when set to high, it would make me suspect that your interior thermostat isn’t communicating…
The only other thing I can think of as it relates to a potential coolant issue is that you somehow entrained air in the system. Have you tried a "burp" procedure by chance?
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- #15
I haven't, how do I do that?
Lots of YT videos and guides out there, but here's the gist. With a cold engine, remove the radiator cap. Start the vehicle with the radiator cap removed and crank the heat full blast, front and rear passenger. Let the engine temp climb to operating temp during all that. Gently squeeze some of the surrounding coolant hoses (be careful obviously). If the coolant level dropped at all from the radiator cap, you had air in the system. Fill as necessary from the radiator cap. Put the radiator cap back on. Then fill your reservoir if needed after the rad is full.
bloc
SILVER Star
Some 2016+ had issues with the air metering doors in the dash doing odd things, that would be my focus. You can initialize them with techstream to see if that gets them working.
Modern cooling systems are really good about keeping air out of the parts it shouldn’t be in, as long as the level is high enough. At L or even a bit below it should be plenty, I don’t see any reason to burp the system.
If you want a little confirmation open the hood and check whether the heater lines on the passenger side of the engine bay get hot as the engine warms up from cold. They should get warm water pretty quickly, probably even before you’d feel the radiator warming up, as the system is set up to prioritize the heater cores for passenger comfort in cold weather.
If those lines get hot you have plenty of hot water, the issue is the doors in the dash not actually allowing air through the core. My gut is that’s the issue here, or maybe a vent temp sensor going bad.
What is your rear heater doing? Make sure it is turned on, set the temp back there to all the way hot, and see what happens.
Modern cooling systems are really good about keeping air out of the parts it shouldn’t be in, as long as the level is high enough. At L or even a bit below it should be plenty, I don’t see any reason to burp the system.
If you want a little confirmation open the hood and check whether the heater lines on the passenger side of the engine bay get hot as the engine warms up from cold. They should get warm water pretty quickly, probably even before you’d feel the radiator warming up, as the system is set up to prioritize the heater cores for passenger comfort in cold weather.
If those lines get hot you have plenty of hot water, the issue is the doors in the dash not actually allowing air through the core. My gut is that’s the issue here, or maybe a vent temp sensor going bad.
What is your rear heater doing? Make sure it is turned on, set the temp back there to all the way hot, and see what happens.
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- #18
Both hoses are warm. The far rear vents in the ceiling are warm, front and second row vents run cold. The issue then is the doors in the dash or heat sensor? Thoughts on next steps?
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- #19
Also, this happened after a lot of rough dusty trail driving if that makes difference.
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- #20
More. I just found this. "HVAC Blend Door Actuator - Repair or Replace if air is coming out of the wrong vents or at the wrong temperature, or if you’re hearing a strange rhythmic clicking noise from your dashboard, your Toyota Land Cruiser may have a failed blend door actuator" Toyota Land Cruiser Hvac blend door actuator. Air, wrong, conditioning - 8710660120 - Genuine Toyota Part - https://parts.toyota.com/p/Toyota__Land-Cruiser/HVAC-Blend-Door-Actuator/63371522/8710660120.html
Yes wrong vent and yes wrong temp and yes rhythmic clicking sound in Nebraska on my way home which I didn't think of until now.
