2008 jk : Heat on passenger side only

DLiT

New member
Need some guidance, I’ve only got heat on the passenger side vents. The far right is the hottest, and they get progressively colder. The driver’s side is not warm at all. I have an 08 Jeep Wrangler. I get cold A/C out of every vent, but when I switch it to heat I only get it out of the passenger side. I’m thinking the Control knob for hot and cold air is not properly closing all the way. I picked up a replacement blend door actuator and was hoping for some guidance on switching it out. Is this the right part for what I’m talking about?



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rumblebee3

Caught the Bug
Need some guidance, I’ve only got heat on the passenger side vents. The far right is the hottest, and they get progressively colder. The driver’s side is not warm at all. I have an 08 Jeep Wrangler. I get cold A/C out of every vent, but when I switch it to heat I only get it out of the passenger side. I’m thinking the Control knob for hot and cold air is not properly closing all the way. I picked up a replacement blend door actuator and was hoping for some guidance on switching it out. Is this the right part for what I’m talking about?



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I am going through these exact same issues right now but I have a head gasket leak. So I believe my problem is a flow issue. Had somebody check it out and confirm that the blend door was working correctly so you might try flushing your heater core both ways with a garden hose. But be sure not to put too much pressure to it as you can blow the​ heater core out. I already flushed mine out both directions multiple times and got plenty of flow. When I reassembled everything, still have the same issue. I believe my issue is lack of flow due to the head gasket pushing all the water out of the system.

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rumblebee3

Caught the Bug
Need some guidance, I’ve only got heat on the passenger side vents. The far right is the hottest, and they get progressively colder. The driver’s side is not warm at all. I have an 08 Jeep Wrangler. I get cold A/C out of every vent, but when I switch it to heat I only get it out of the passenger side. I’m thinking the Control knob for hot and cold air is not properly closing all the way. I picked up a replacement blend door actuator and was hoping for some guidance on switching it out. Is this the right part for what I’m talking about?



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Forgot to mention mine is the exact same year as yours

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moreno47

New member
I have a 2007 JKU X. I had the same problem. I did just about everything. Flushed the radiator, replaced the thermostat, back flushed the heater core but nothing worked. I finally got heat back this weekend. A friend of mine let me borrow his condensate pump and I circulated CLR, for 12 hours, circulated vinegar for 12 hours, flushed hot water for 20 minutes then flushed DI WATER for 20 minutes. Then filled the hoses with antifreeze, burped the system with a spill free funnel, and finally got heat back. Real good heat. I have a soft top in northern Illinois, you need heat up here, it’s been really cold.


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moreno47

New member
Things that I have been reading is that with the newer JKs there was a casting sand issue that was clogging radiators and heater cores. The blender door was also a problem because the newer JKs operated by a motor. The older JKs have a cable that operates the blender door. So unless the cable fell off the the blender door wouldn’t operate. Which I think is unlikely. It sounds like you have a partially blocked heater core or scale build up it could be also that you have a bubble in your cooling system.


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DLiT

New member
Things that I have been reading is that with the newer JKs there was a casting sand issue that was clogging radiators and heater cores. The blender door was also a problem because the newer JKs operated by a motor. The older JKs have a cable that operates the blender door. So unless the cable fell off the the blender door wouldn’t operate. Which I think is unlikely. It sounds like you have a partially blocked heater core or scale build up it could be also that you have a bubble in your cooling system.


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How can I get that bubble out? I’ll try that first before diving into the serious flushing that was mentioned above. CLR, Vinegar, and Distilled is definitely coming up next though!



▪️2008 JK (2-Door Sahara)
▪️Manual Transmission
▪️Rubicon Dana 44’s w/ E-Lockers
▪️37” Trepadors
▪️Hutchinson Rock Monsters
▪️Teraflex Front Big Break Kit
▪️King Shocks
▪️12k Warn Winch
 

moreno47

New member
How can I get that bubble out? I’ll try that first before diving into the serious flushing that was mentioned above. CLR, Vinegar, and Distilled is definitely coming up next though!



▪️2008 JK (2-Door Sahara)
▪️Manual Transmission
▪️Rubicon Dana 44’s w/ E-Lockers
▪️37” Trepadors
▪️Hutchinson Rock Monsters
▪️Teraflex Front Big Break Kit
▪️King Shocks
▪️12k Warn Winch

What I did was I bought a spill free funnel system. It was $30 from NAPA.

https://shop.advanceautoparts.com/p...VDbnACh2Ggg02EAQYASABEgK08PD_BwE&gclsrc=aw.ds

I know they sell it cheaper else where, or you can get the largest funnel you can find and use tape to make it fit snug. There are some YouTube videos on how to burp your coolant system.

https://youtu.be/xYkKW0OyeUc

Hopefully this helps. I got some good air bubbles as my jeep was running. You should let run for at least 2 cycles of your cooling fan.


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DLiT

New member
What I did was I bought a spill free funnel system. It was $30 from NAPA.

https://shop.advanceautoparts.com/p...VDbnACh2Ggg02EAQYASABEgK08PD_BwE&gclsrc=aw.ds

I know they sell it cheaper else where, or you can get the largest funnel you can find and use tape to make it fit snug. There are some YouTube videos on how to burp your coolant system.

https://youtu.be/xYkKW0OyeUc

Hopefully this helps. I got some good air bubbles as my jeep was running. You should let run for at least 2 cycles of your cooling fan.


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Awesome, and I have a spill free funnel sitting in my garage, gonna check it out now. Thanks brother!



▪️2008 JK (2-Door Sahara)
▪️Manual Transmission
▪️Rubicon Dana 44’s w/ E-Lockers
▪️37” Trepadors
▪️Hutchinson Rock Monsters
▪️Teraflex Front Big Break Kit
▪️King Shocks
▪️12k Warn Winch
 

moreno47

New member
Something else that might help is to jack the jeep up on the front driver side, just to help make that the highest point. You might have an air bubble if you broke into the cooling system to replace the thermostat or something like that.


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DLiT

New member
Something else that might help is to jack the jeep up on the front driver side, just to help make that the highest point. You might have an air bubble if you broke into the cooling system to replace the thermostat or something like that.


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I did, I’ll make sure to lift it up passenger side since that’s the side with the radiator cap.



▪️2008 JK (2-Door Sahara)
▪️Manual Transmission
▪️Rubicon Dana 44’s w/ E-Lockers
▪️37” Trepadors
▪️Hutchinson Rock Monsters
▪️Teraflex Front Big Break Kit
▪️King Shocks
▪️12k Warn Winch
 
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