Question about interior heating...

[DHW]

Posted this earlier on an old thread and didn't realize it was a few years old.

I'll preface this by saying I never use the Auto climate, always set the temp and fan manually. Yesterday I had to take a work call in my Jeep which was cold as I had been at the office for a few hours. I started the Jeep and let it idle during the call to keep warm, but didn't go anywhere. I had the temp set at max temp, but noticed that the air wasn't all that warm even after the engine warmed up. I lightly pressed the gas holding the RPMs at around 1200, which caused the air to get the level of warmth it should have been at on max temp. When I let off the gas, the air cooled back down a bit. I did this a few times with the same result. I guess I never noticed this before because I basically never just sit and idle for any period of time.

Any explanation for that? Is that normal? If it makes any difference, Jeep is a 2018 Rubi with the 2.0 eTorque, about 42k miles.

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[Flip]

Have you checked your coolant level recently? Do you think there is a chance there might be air in the radiator?

I would also check your air cleaner to make sure there isn't a mouse nest in it.

 

[Old Jeeper]

Posted this earlier on an old thread and didn't realize it was a few years old.

I'll preface this by saying I never use the Auto climate, always set the temp and fan manually. Yesterday I had to take a work call in my Jeep which was cold as I had been at the office for a few hours. I started the Jeep and let it idle during the call to keep warm, but didn't go anywhere. I had the temp set at max temp, but noticed that the air wasn't all that warm even after the engine warmed up. I lightly pressed the gas holding the RPMs at around 1200, which caused the air to get the level of warmth it should have been at on max temp. When I let off the gas, the air cooled back down a bit. I did this a few times with the same result. I guess I never noticed this before because I basically never just sit and idle for any period of time.

Any explanation for that? Is that normal? If it makes any difference, Jeep is a 2018 Rubi with the 2.0 eTorque, about 42k miles.

Mine does the same thing, crazy, you play with it to get hot air...

 

[AFD]

Mine does the same thing, which makes the remote start essentially useless. I can start it up and let it idle for 10 minutes and get in and it's still just blowing cool air. Usually takes a few minutes of driving until it decides to blow warm air.

On really cold days I'll still use the remote start just to get the fluids moving for a minute, but for warming the vehicle, it's just a waste of gas.

 

[Bob Burd]

That ain't right. I sleep in my Jeep on trips and start it in the morning to warm things up. Works great. With remote start, it blows cool air to defog until start button is pressed.

 

[zakaron]

As Flip mentioned, I would check coolant level first. If it is low enough it won't circulate well enough through the heater core. If the level is fine, I would consider a coolant flush even though you don't have that many miles on it. While you are doing the flush, I would also backflush the heater core. I haven't studied the JL closely enough yet, but other cars that I've had this same issue on, I would disconnect the inlet and outlet hoses going to the heater core. I would then rig up a way to get a garden hose to blow water back through the outlet side and then catch what comes out the inlet side in a bucket. Usually there is sludge and debris buildup that causes it to circulate poorly at low RPM.

 

[Wbino]

Use the auto, it's pretty smart.
No remote start I'm guessing?

 

[HDSlowride]

My '21 JLUR has a similar problem in cool weather. If I set the heat control to "auto", it won't circulate hardly any air even when fully warmed up and the temperature control set above 80 degrees. Nothing comes out of the two vents in the rear of the console for rear seat heat.

I can switch over to manual heat controls and pick any fan speed and it will blow lots of hot air. Except still nothing, or very little, out the rear vents.

Turn it back to "auto" and it almost stops blowing, even while still cold in the interior and temp controls set very high (80+). Nothing like any other late model vehicle I've ever owned.

 

[Heimkehr]

I started the Jeep and let it idle during the call to keep warm, but didn't go anywhere. I had the temp set at max temp, but noticed that the air wasn't all that warm even after the engine warmed up. I lightly pressed the gas holding the RPMs at around 1200, which caused the air to get the level of warmth it should have been at on max temp. When I let off the gas, the air cooled back down a bit. I did this a few times with the same result.

Any explanation for that? Is that normal?

Possibly it's normal on those JLs with so-called Auto climate control functioning. I've the three analog HVAC dials in my Jeep (i.e., there's no separate on-screen temperature inputs or displays) and when idling the interior will get warm, or hot, in proportion to the position of the center temperature dial. 2.0T here also.

There are several forum threads where the discussion does center on the Auto climate control not acting in accordance with its setting, and/or what the owner is expecting to occur in terms of heat or cooling output. Maybe it's just a documented whiff in the original design or functioning of the Auto climate controls.

 

[Bill_BCNtoNY]

IMHO, auto climate controls belong in the same hell as modern microwaves.

I just want my dials back please (although I admit I preferred a trim that allowed a bunch of other stuff I did want) - in Jeep that’d be temp, fan speed and vent controls. In the microwave just time and power please!

 

[Flip]

Possibly it's normal on those JLs with so-called Auto climate control functioning. I've the three analog HVAC dials in my Jeep (i.e., there's no separate on-screen temperature inputs or displays) and when idling the interior will get warm, or hot, in proportion to the position of the center temperature dial. 2.0T here also.

There are several forum threads where the discussion does center on the Auto climate control not acting in accordance with its setting, and/or what the owner is expecting to occur in terms of heat or cooling output. Maybe it's just a documented whiff in the original design or functioning of the Auto climate controls.

When my heat is on full blast every once in a while, I notice the fan/blower has a tendency to rise up and then drop back down. It acts as if I turned the fan too low for two seconds and then turned it back on high. It will do this both while driving and at idle, idk weird.

 

[NPC 20883467]

What has been noticed previously but not often mentioned is the fact that when the JL is idling in Park, the damned air conditioning compressor cycles on and off, regardless of what you have the AC controls set to. As soon as you put it in drive, the compressor turns off, if indeed it's supposed to be off. It's maddening as hell when you're trying to de-ice the windshield.

As a workaround in the fall, when I know I'm not going to need AC anymore, I pull the AC compressor relay out of the fuse panel.

 

[DHW]

Use the auto, it's pretty smart.
No remote start I'm guessing?

I do have remote start, I just live in GA so I never need it. Plus my 2.0 gets up to operating temp faster than any car I’ve ever had.

I just checked the coolant and it’s perfectly halfway between max and min.

I’m fairly certain it’s just the normal operation, for whatever reason.

 

[Heimkehr]

What has been noticed previously but not often mentioned is the fact that when the JL is idling in Park, the damned air conditioning compressor cycles on and off, regardless of what you have the AC controls set to. As soon as you put it in drive, the compressor turns off, if indeed it's supposed to be off.

Not mentioned possibly because that's the first I've seen it mentioned since joining the forum in 2020. I've not ever observed the described compressor behavior in my Jeep, either, which also dates to 2020.

Maybe it's an electronic gremlin in your JL that needs investigating? Or perhaps it's otherwise functioning normally in those Wranglers that have the more complex HVAC system; i.e., those with the "Auto" temperature feature.

 

[Vinman]

What has been noticed previously but not often mentioned is the fact that when the JL is idling in Park, the damned air conditioning compressor cycles on and off, regardless of what you have the AC controls set to. As soon as you put it in drive, the compressor turns off, if indeed it's supposed to be off. It's maddening as hell when you're trying to de-ice the windshield.

As a workaround in the fall, when I know I'm not going to need AC anymore, I pull the AC compressor relay out of the fuse panel.

You know the A/C compressor will cycle in most vehicles if the “defrost” setting is selected, right?
It will probably also cycle when “auto” is selected.

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