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Heater is not working

12K views 12 replies 6 participants last post by  eriktiatco 
#1 ·
I tried to look for a thread with this problem could not find any.
Anyway, I took a 2600miles trip, from Southern Cali, to Virginia, and arrived 4 days ago, I tried to turn the heater on, but it only blows cool air, and no its not on a/c setting, does any one knows what could be the problem? I opened the hood to look for what I don't know, but noticed the Radiator container cap was loose, could this be the problem?:confused:
 
#2 ·
The loose cap isn't the cause of no heat. There is a valve in the heater water line that opens when heat is called for. It sounds like this valve is not opening. You can see the valve mounted on a bracket off the firewall on the passenger side(under the hood). It has hoses connected to it.
However there is nothing you can do to check it out, you will have to go to the dealer.
Even though you said it is not set on A/C, I still have to ask - Do you have the temp controll set to hot?
 
#3 ·
scr38 said:
The loose cap isn't the cause of no heat. There is a valve in the heater water line that opens when heat is called for. It sounds like this valve is not opening. You can see the valve mounted on a bracket off the firewall on the passenger side(under the hood). It has hoses connected to it.
However there is nothing you can do to check it out, you will have to go to the dealer.
Even though you said it is not set on A/C, I still have to ask - Do you have the temp controll set to hot?
Yup, it was set to maximum heat, I guess I'll make this trip to the dealer
 
#4 ·
scr38 said:
The loose cap isn't the cause of no heat. There is a valve in the heater water line that opens when heat is called for. It sounds like this valve is not opening. You can see the valve mounted on a bracket off the firewall on the passenger side(under the hood). It has hoses connected to it.
However there is nothing you can do to check it out, you will have to go to the dealer.
Even though you said it is not set on A/C, I still have to ask - Do you have the temp controll set to hot?
SCR, does it make a difference if the water( antifreeze ) level in the radiator reserve tank was low?
 
#5 ·
recheck you coolant level, it has to be where it is marked on the reserve tank, I had a similar problem, and that was the cause of it. also if you say your radiator cap was loose you may have lost it through their.cap must be on tight . you also may have to blead the system being that radiator cap being loose took in some air.
there is a tsb on the radiator cap being faulty, something to do with the gasket, if the gasket is deformed you may need a new cap.
 
#6 ·
If the coolant level was low enough to get air into the system that could be the problem.
Just to clear things up, there are two caps here, one on the radiator and one on the reserve tank. Unlike many systems, the Armada's reserve tank is under pressure. The cap on the radiator isn't a pressure release cap, it just seals. That is the cap that there have been problems with. On some early caps the rubber gasket expanded and let the system leak. There is a TBS on that cap.
The cap on the reserve tank is the pressure cap. It must be tight at all times also. If the coolant level in the reserve tank gets very low then air could be drawn into the radiator as the system cools and the coolant contracts.
 
#8 ·
update

Thanks guys for all the responses, it will only be fair to update you.
SCR,he coolant was very low, so I decided instead of going to the dealer, to stop by the auto store and buy a gallon of antifreeze, I poured more than 3/4 into the Radiator resevoir, and drove for a while, then let it cool for a while. and added the rest of the antifreeze. and started the heater again and its working. thanks for all your input. it was a close call driving 2600miles almost no coolant:cool:
 
#9 ·
Now the question is where did the coolant go? Do you see any signs of a leak? Be sure to keep an eye on the level.
 
#11 ·
ggeorgie said:
Thanks SCR, will do. As for the coolant I believe it did evaporate during the trip, driving 10 to 12 hours a day straight. but still I 'll keep an eye on the level.

I just drove a few 5 to 9 hour days on a tour around the UAE and OMAN in temps upto 100 degrees F with no loss of coolant. I would check for leaks or a bad cap.
 
#12 ·
Thanks Tmation, I did the same tour many years ago, from Al-Ain UAE to Oman and back to Dubai, never had any problems, even with all the heat of the desert, and now I had no problems as for overheating after driving 2600 miles except the loss of coolant and the heater does not blow hot air, coming to find out that the CAP was loose ( Very loose ). so I added more coolant and now the heater is working fine, and am keeping an eye on the coolant level:cool:
 
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