rear heater temperature values

[deathfry]

good day

I am trying to find exact numbers what temperature from the rear heater should be considered as normal. For ex. I have -30C outside and it blows from the ceiling (middle vent strength position) about 32C. Is it ok? Or it should be higher?

 

[Marky Dissod]

If you could get your hands on a Field Service Manual, you'd have the answer to your question.

32C is 89.6F, which is about as hot as most automotive HVAC systems claim to be able to get.
Are you trying for even warmer air? Or to make it heat up more quickly?
You might want to start by checking the rest of the cooling system, make sure everything works to spec.

I'm hoping to figure out how to warm up my Tahoe more quickly, but once up to temp, it's almost hot enough to reheat food in there.

 

[deathfry]

Well, in my front heater there is 70C (yes, celsium) when I turn into the face and with the blower in the middle position. I thought that the rear heater should be as effective as the front.

And I think my front heater is not so effective when it takes legs: it blows to the legs (so the actuator is working) but not so effective. I think it should be more warmer like when it is blowing in the face.

 

[Marky Dissod]

EVENTUALLY, the rear heater may be as effective as the front, but it has to pass over a far greater distance, through much more colder materials, so I think that would take more time to hit 158F.

What thermostat does your engine use? I wonder if there is a warmer one available?
There are probably other things you can do, but in NYC under -20C is record breaking cold.

 

[deathfry]

EVENTUALLY, the rear heater may be as effective as the front, but it has to pass over a far greater distance, through much more colder materials, so I think that would take more time to hit 158F.

What thermostat does your engine use? I wonder if there is a warmer one available?
There are probably other things you can do, but in NYC under -20C is record breaking cold.

Am I getting it right: it is ok to be 32C in the rear on the idle? If yes then I should stop wondering and start finding out why there is very little air flows out from legs mode
BTW how much do you have in the rear? and could you please provide link to the "field service manual" with the temp page?

 

[89Suburban]

It’s my humble opinion out of all vehicles I have owned in my lifetime the floor heat flow sucks on these GMT900’s unless you crank it up to 4-5 speed then you got to deal with the fan noise.

 

[Doubeleive]

Am I getting it right: it is ok to be 32C in the rear on the idle? If yes then I should stop wondering and start finding out why there is very little air flows out from legs mode
BTW how much do you have in the rear? and could you please provide link to the "field service manual" with the temp page?

rear always takes longer to heat up will never match the front, the lines have to travel to the rear of the vehicle (exposed to outside cold air) then the air has to blow forward nearly half the vehicle. if you choose the roof vent it then is also exposed to colder outside temps of the roof. all in all probably 20x the distance of the front air
the front is right near the engine and travels only a short distance.

if you need more heat in the rear wire up some 12v electric heaters for the back. I would if was that freaking cold....
-22Deg F would make me insulate my vehicle as necessary, if it was like that often or for a extended period.
probably with something like wool

 

[deathfry]

It’s my humble opinion out of all vehicles I have owned in my lifetime the floor heat flow sucks on these GMT900’s unless you crank it up to 4-5 speed then you got to deal with the fan noise.

• 2000 - 2006 Tahoe/Yukon/Escalade Models - this topic is about older 800 models) I actually own a 2004 tahiti

 

[deathfry]

rear always takes longer to heat up will never match the front, the lines have to travel to the rear of the vehicle (exposed to outside cold air) then the air has to blow forward nearly half the vehicle. if you choose the roof vent it then is also exposed to colder outside temps of the roof. all in all probably 20x the distance of the front air
the front is right near the engine and travels only a short distance.

if you need more heat in the rear wire up some 12v electric heaters for the back. I would if was that freaking cold....
-22Deg F would make me insulate my vehicle as necessary, if it was like that often or for a extended period.
probably with something like wool

no need for that, it is rare to have such temperature and front heater compensates weak rear heater

I just wanted to find out certain values of degrees that are considered as normal
Or at least delta between front and rear that is considered to be normal (for ex. if it exceed 20 degrees between front and rear it is not good)

 

[Doubeleive]

no need for that, it is rare to have such temperature and front heater compensates weak rear heater

I just wanted to find out certain values of degrees that are considered as normal
Or at least delta between front and rear that is considered to be normal (for ex. if it exceed 20 degrees between front and rear it is not good)

I am sure there is a spec listed that the dealer would have used to determine if it is correct or not. It's going to be in the dealer service manual-somewhere under troubleshooting
the only thing that you could do to insure it is correct otherwise is
1. visually inspect the hot/cold actuator/door (rear closest to blower motor)
2. replace rear heater core (if it is perhaps clogged up)

 

[89Suburban]

• 2000 - 2006 Tahoe/Yukon/Escalade Models - this topic is about older 800 models) I actually own a 2004 tahiti

Sorry I couldn’t tell on mobile doesn’t show it unless the phone is sideways and I don’t do sideways except in the babe of the day thread

 

[Marky Dissod]

Am I getting it right: it is ok to be 32C in the rear on the idle?
If yes then I should stop wondering and start finding out why there is very little air flows out from legs mode
BTW how much do you have in the rear? and could you please provide link to the "field service manual" with the temp page?

I'd say, ten minutes after it passes 33C, how much hotter does it get?
If it can get hotter than that, then yes, time to find out why you're not getting enough air from feets mode.

 

[deathfry]

I'd say, ten minutes after it passes 33C, how much hotter does it get?
If it can get hotter than that, then yes, time to find out why you're not getting enough air from feets mode.

FRONT HEATER: I made some research on past weekend: it shows 156F in the feet. Maybe I can't feel it cause of vents location
On my prev Dodge Caliber it was more sensitive

 

[deathfry]

just for the history if someone will be curious:

tahoe 2004 5.3 idling
it is -16C (3.2F) outside
rear heater vent is little below middle position, temp is set to red, ceiling (see attach)
temperature became 42.9C(107.6F) in about 15 minutes from the start (but it wasn't cold start, the car was little warm)

pump is new and original
antifreeze is full as should be

 

[Doubeleive]

just for the history if someone will be curious:

tahoe 2004 5.3 idling
it is -16C (60.8F) outside
rear heater vent is little below middle position, temp is set to red, ceiling (see attach)
temperature became 42.9C(107.6F) in about 15 minutes from the start (but it wasn't cold start, the car was little warm)

pump is new and original
antifreeze is full as should be

that temp will come out a bit different when it is freezing outside

 

[deathfry]

-16С (3.2F) is considered as freezing? it is winter outside)