No rear heat? (front works fine)

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porksoda
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No rear heat? (front works fine)

Postby porksoda » Fri Jan 01, 2016 10:03 pm

I am having an issue with my rear heat.
My front vents blow out nice hot air, but the rear only blows out cold.
I know the rear used to blow hot air out in the past. My daughter sits in the back and I am always driving. My wife decided to drive and I sat in the back for the first time in a long time and noticed it is only blowing cold. I checked to make sure that all controls are on heat, but still blowing cold.

Any suggestions would be appreciated!


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disallow
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Postby disallow » Fri Jan 01, 2016 11:23 pm

Low coolant. Fill 'er up! :)

I've had to do this twice over the past 5 yrs or so.

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porksoda
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Postby porksoda » Fri Jan 01, 2016 11:52 pm

Well I went to check and the coolant level was just a hair lower then max. I went on ahead and filled it up a little more then max. I ran it for 30 mins and the front air was nice and hot but the rear was ice cold. I wonder what is the next step I should do. Maybe a pressurized coolant exchange?

I checked the radiator and it is full also.

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smj999smj
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Postby smj999smj » Sat Jan 02, 2016 5:46 am

Set all of the heaters to the maximum heat position, jack up the front end of the vehicle, and run the engine between 2000-3000 RPM for about 15-20 minutes until the rear heater blows hot. If that doesn't work, you may have a bad heater pump (located at the firewall and has two heater hoses connected to it) or possibly a bad mode door actuator on the rear heater unit.

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porksoda
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Postby porksoda » Sat Jan 02, 2016 6:46 am

smj999smj wrote:Set all of the heaters to the maximum heat position, jack up the front end of the vehicle, and run the engine between 2000-3000 RPM for about 15-20 minutes until the rear heater blows hot. If that doesn't work, you may have a bad heater pump (located at the firewall and has two heater hoses connected to it) or possibly a bad mode door actuator on the rear heater unit.
With the vehicle lifted up and rps up do I leave any of the caps open(radiator or overflow tank)?
Thanks!

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Postby skinny2 » Sat Jan 02, 2016 7:14 am

I've had this problem in the past and I park on a steep incline with the nose up (in lieu of jacking the front) and open the radiator cap (with a cold engine of course!!). Set the heat to max and let the engine warm up. Once the coolant starts flowing rev the engine as smj999smj stated. Some will spill out of the radiator but that seems to be part of the "burping" process. Then top off the tank and close everything up. Sometimes it will still blow luke-warm air to the back if you're idling or driving slowly, but once rolling the heat returns. I don't know if the pump is weak or what but it's been like this for years. Rear heat isn't a big enough deal for me to do any more than what I've done.

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smj999smj
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Postby smj999smj » Sat Jan 02, 2016 1:33 pm

I leave the caps on. My friend has a 2004 Tiitan that had poor heating issues and he fixed it by replacing the heater pump and purging it the way I just explained in the earlier post.

DanJetta
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Postby DanJetta » Sat Jan 02, 2016 1:41 pm

Yep, I have to do this every year to get my rear heat to work for the winter.

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disallow
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Postby disallow » Sat Jan 02, 2016 10:25 pm

The only time I've bothered with ramps is when I drained the system totally. Otherwise, I've never had to do that to get rid of any air pockets. IMHO you should check the fluid level. If low, add some and see what happens. If the heat doesn't come back, try ramps to get more air out.


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