Well, im starting to get tired of my Titan. Its about 85 here today I ran the AC in my T. After turning the key off there was some clicking behind the dash...upon turning the key on I heard the same noise...also when I turned the temp adjustment knob. Well I was messing with knob trying to get the noise to stop,and found out my heater is warm, but not hot. Like i said its 85 hers today and I would think my heat would get pretty damned warm quick on a day like today. I took the cover off the valve on thr firewall...some junk *** looking plastic gears/worm gear...didnt have time to mess with it much, so i put it back together for now...anybody have this problem?
Heater control valve???
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I took it apart and used a screw driver to turn it back and forth a few times...it seems to spin 360 degrees, which doesnt seem right to me...anyway...i worked it back and forth a few times and now it seems to only hum or buzz slightly and my heat and AC are both working. Is this valve either 100% or 100% closed? Is it supposed to turn 360 degrees?
I believe it will open and close as much as the heater control demands. That is, I don't think it just goes all the way in either direction. See my other posts about this. The valve part gets stuck from non-use (leaving it in AC in the summer), but frees up easily with just a few back and forth's, as you found. See my other post about replacement. Nissan doesn't call it a heater control valve, they call it a heater hose assembly. (yes, two hoses with an electronic box in the middle!)
So it will always allow some amount of coolant to reach the heater core? Not gonna mess anything up per say by running the AC if the valve isnt all the way closed. Does yours make a sound? Mine was quite loud, now like I said its more of a buzz or hum, an electric motor sound. Cant make up my mind if the noise itself is reason enough to replace it. Thanks for the input.
By the way, why its designed so that the valve itself cannot simply be disconnected from the hoses and replaced is beyond me....just a way for them to charge peoole $500 to fix it I guess. How hard is it to replace? Any good way to cut the hoses and splice the old ones to the new ones ?
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40 Posts
hotshot,
honestly just opening it is fine. Summer was mild by Jersey standards but even on our hot days past 90 with it left open noticed no decrease in performance and my heat works which is the real bonus. Pain the *** to replace as the hose is at the back of the motor and difficult to reach. Your only limited by your imagination on how you want to replace it or deal with it and there has been some really interesting workarounds if you search the forum. If I was insane as I used to be would have replaced it already. Now when I see the hoses leaking I'll replace with new then and have it put coolant into my climate system for now.
honestly just opening it is fine. Summer was mild by Jersey standards but even on our hot days past 90 with it left open noticed no decrease in performance and my heat works which is the real bonus. Pain the *** to replace as the hose is at the back of the motor and difficult to reach. Your only limited by your imagination on how you want to replace it or deal with it and there has been some really interesting workarounds if you search the forum. If I was insane as I used to be would have replaced it already. Now when I see the hoses leaking I'll replace with new then and have it put coolant into my climate system for now.
I guess they figured when it's time to change the valve, you might as well changes the hoses, too. Normally, that's a good practice, but in reality it depends on access to the other ends.
There are many auto HVAC systems that employ both the heater core and the AC at the same time. Especially when heat alone, perhaps in defrost mode, makes it more steamy. The AC dehumidifies the air. The air blend/mixer door is part of this, too.
As far as noise, I don't hear mine at all. But I wouldn't worry about a little hum as the motor rotates the valve. I would not expect it to be a constant hum, however.
As for prices of the assembly, as I noted in the other boards, I see prices from $90 to $140 on EBay, and $160 - $180 from Nissan. Not real bad, given the complexity of the assembly.
There are many auto HVAC systems that employ both the heater core and the AC at the same time. Especially when heat alone, perhaps in defrost mode, makes it more steamy. The AC dehumidifies the air. The air blend/mixer door is part of this, too.
As far as noise, I don't hear mine at all. But I wouldn't worry about a little hum as the motor rotates the valve. I would not expect it to be a constant hum, however.
As for prices of the assembly, as I noted in the other boards, I see prices from $90 to $140 on EBay, and $160 - $180 from Nissan. Not real bad, given the complexity of the assembly.
How freely back and forth does the main, larger gear move on a working unit? I was able to get my heater and AC to function again by turning that gear clockwise and counter-clockwise numerous times, but it takes quite a bit of effort. The dealer wants $400+ to replace this unit, but your instructions seem to have addressed the issue...even if only temporarily?
I removed all the gears, leaving only a plug with a slot in it, square in line with the fluid inlet and outlet. It appeared I could pull it towards me, but that would have let the fluid to pour out. That's the piece I rotated left and right, 180 degrees each way. The first time was the hardest, and I worked slowly as to not rip an o-ring. Once loosened, I was able to turn it left and right with about the force of turning a regular doorknob. Then I put the gears back together, put the cover on, and worked it a few times from inside, switching from full cold to full hot. I have since done that every month or so, even in hot and cold weather, so it doesn't harden in place again. BTW, be careful with those little gears, they could drop out easily. That's why I didn't operate it with the cover off.
what is its purpose? Most vehicles dont have a valve like this. Hot / cold is controlled my moving an interior door near the blower motor which directs air over the heater core or a/c evaporator, or a combination of them both. why would you need to cut off coolant from entering the heater core?
Actually, a heater control valve in the coolant line is an old technique. My friend's 1953 Hudson has one, and I've had them over the years in about 1/2 the vehicles I've owned. Yes, the heater/AC box can be used with moving airway doors, but need to be stronger and tighter (and thus more expensive) if needed to keep the radiant heat from entering the passenger compartment. Depending on settings, a modern (computerized) HVAC might be requesting a blend of some heat, some AC, and some fresh air, depending not only on temp, but also humidity. Controlling three inputs with flapper doors could be complicated. Evidently Nissan has opted to control the heat with a fluid valve.
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3,550 Posts
I have one of these Heater Control Valves (Brand New) and would be willing to sell it if anyone is interested.
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Greetings,
I know this post is from a while back but I figured I would give it a go anyway. Do you still have the part and would it fit my 2008 Nissan Titan? If so please let me know so we can make arrangements. Thanks for your time.
Bob
I know this post is from a while back but I figured I would give it a go anyway. Do you still have the part and would it fit my 2008 Nissan Titan? If so please let me know so we can make arrangements. Thanks for your time.
Bob
how much for the valve assembly picklesmoocher?
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2 Posts
Hi there,
as like everyone on this form i am having trouble with my heater valve on my 2010 Titan. I managed to get the heat working but now have to manually unscrew it and turn it with a screw driver. So, I've decided to replace the part and bought one off Rock Auto.
I was just curious on how to remove the hoses? do i need to be worried about coolant or fluid coming out of the lines when i remove them? Has anyone on this forum done this procedure ?
Was looking for a tutorial on youtube, but i can't find any of people replacing the entire until . Any feed back will be greatly appreciated.
Thanks
as like everyone on this form i am having trouble with my heater valve on my 2010 Titan. I managed to get the heat working but now have to manually unscrew it and turn it with a screw driver. So, I've decided to replace the part and bought one off Rock Auto.
I was just curious on how to remove the hoses? do i need to be worried about coolant or fluid coming out of the lines when i remove them? Has anyone on this forum done this procedure ?
Was looking for a tutorial on youtube, but i can't find any of people replacing the entire until . Any feed back will be greatly appreciated.
Thanks
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