19963.4lsr5
New member
That looks like a coolant flush setup using your garden hose.
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So Who's had To Replace Their Heater Control Valve?
- Thread starter blaze17
- Start date
I know, holy thread revival Batman. The previous crackhead/owner decided to use a highlighter. I wouldn't suggest it, but I guess it made the trip from Los Angeles to Detroit. Just ordered a replacement 4 seasons part from amazon. I can't wait to see what else this thing has.
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Sparky 97Runner
New member
Haha, that's awesome. I wouldn't hesitate to do something like that myself as a temp fix to get off a trail or limp back home. But yeah, definitely not a permanent install for a cross country road trip.
jgue467
Senior Member
Stupid heater control valves. Its one of the few things gone south on mine too, Twice in 338K!
I do like the repurposing of the highlighter though. Went to visit Puerto Rico once for a few weeks, amazing what those folks do to get by on auto reparis while not ordering parts!
I do like the repurposing of the highlighter though. Went to visit Puerto Rico once for a few weeks, amazing what those folks do to get by on auto reparis while not ordering parts!
My dad bought it at an auto auction for like 1800 last year. I'd say it was a great buy though there's bailing wire holding up the exhaust and there was apparently a leak at the power steering line that goes to the reservoir. Instead of replacing the hose, previous owner hollowed out a pen, put on a couple clamps and got some heater hose to reach after cutting the leaking part off. I really don't understand what went through this person's mind.
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I'm glad this thread popped up because I am new to 3rd gens and wouldn't have known it was a weak point.
My new to me 2002 4runner had a rusty valve bracket so I swapped it with a junkyard one. When I removed my old one it broke pretty easily. The "new" old one is in much better shape but now I want to get a new one to be sure.
These aren't cheap any more, I see OEM is $85. But I'll feel better it's new.
Jason
My new to me 2002 4runner had a rusty valve bracket so I swapped it with a junkyard one. When I removed my old one it broke pretty easily. The "new" old one is in much better shape but now I want to get a new one to be sure.
These aren't cheap any more, I see OEM is $85. But I'll feel better it's new.
Jason
19963.4lsr5
New member
My Napa has lasted 30k miles so far.
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spartacus
Senior Member
The PO did not care that's for sure. You got a bargain, it might take a few hundred dollars to get it into shape. You'll have a great vehicle and with the used price tags on 3rd gens on the upside, a good value.
Dean22
New member
Out of curiosity, why would coolant flow through the heater core when the heater's off? In my experience (admittedly on older cars), the heater is turned on by opening a valve that allows the coolant to flow through the core (plus the fan turns on somehow). Otherwise, there's no flow, so you're not adding unnecessary heat to the cabin.
Thanks,
Dean
EDIT: Nervermind, I see that that was a reference to the return line only. Makes sense now!
Thanks,
Dean
EDIT: Nervermind, I see that that was a reference to the return line only. Makes sense now!
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Quick question about heater control valve
This is my very first post guys so thank you in advance for your expertise and assistance. Recently I have spent a lot of money replacing rack and pinion, power steering pump, air compressor, lines etc. So, I am tapped out. Today I took 3rd gen 4runner (98 Limited, 3.4) to get ac vacuumed and charged. Worked great but the tech said the Heater control valve (HCV for short) was shot and said that if it were working, the temperature inside vehicle would be even colder and in this south texas heat I need colder. He demonstrated by clamping off the driver's side line that connects to the HCV with some vice grips and showed me thermometer. Sure enough...colder. He said I could clamp this line with some vice grips or some type of soft grip vice grips and I could run it like that no problems. Is that correct? I will try to attach a picture and it is the line with the red arrow. Also, I was looking to just bypass the heater core altogether and I saw a post on this forum where a guy said all that needed to be done was disconnect the hose with green arrow, then disconnect the hose with blue arrow and connect it to where the green hose was and connect the green arrow hose to where the blue arrow hose was. Sorry for the long post but I really need help. I could buy a new HCV but after spending so much, I am tapped out. I will fix in the future just need a temporary solution.
This is my very first post guys so thank you in advance for your expertise and assistance. Recently I have spent a lot of money replacing rack and pinion, power steering pump, air compressor, lines etc. So, I am tapped out. Today I took 3rd gen 4runner (98 Limited, 3.4) to get ac vacuumed and charged. Worked great but the tech said the Heater control valve (HCV for short) was shot and said that if it were working, the temperature inside vehicle would be even colder and in this south texas heat I need colder. He demonstrated by clamping off the driver's side line that connects to the HCV with some vice grips and showed me thermometer. Sure enough...colder. He said I could clamp this line with some vice grips or some type of soft grip vice grips and I could run it like that no problems. Is that correct? I will try to attach a picture and it is the line with the red arrow. Also, I was looking to just bypass the heater core altogether and I saw a post on this forum where a guy said all that needed to be done was disconnect the hose with green arrow, then disconnect the hose with blue arrow and connect it to where the green hose was and connect the green arrow hose to where the blue arrow hose was. Sorry for the long post but I really need help. I could buy a new HCV but after spending so much, I am tapped out. I will fix in the future just need a temporary solution.
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I wouldn't clamp it if I was you. Putting the blue arrow hose where the green arrow hose currently is will bypass the heater core completely.
Thank you very much. So if I put the blue arrow hose to where the green is, where do I put the green arrow hose? Where the blue was? And will this keep how water from flowing to heater core so that my ac cools as much as possible? If it weren't for BAD LUCK, I'd have no luck at all! Thanks
brillo_76
Elite Member
Get a Nipple the same size as the diameter of the heater valve and clamp both sides of the clamp green and red together. Use spring clamps or radiator screw clamps to hold the hoses on so they won't seep. I don't think the hose is long enough to go from the driver side of the heater valve to the heater core pipe coming out if the firewall. 
To Elimate the core nipple blue and red together.
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To Elimate the core nipple blue and red together.
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jgue467
Senior Member
Not bad luck when it comes to the 4runner heater control valve.
I wonder which company made them and continuous making them.
On my Runner, it is the Only part replaced Twice in its nearly 342,000, WOW.
Just got in and saw the replies. Thank you for all suggestions, appreciate it. brillo76, definitely interested. Is there a website or how would I be able to get one of your HCVs? I really don't think I can DM in this forum...today was my first post so not sure how to proceed. Please advise.
Get a Nipple the same size as the diameter of the heater valve and clamp both sides of the clamp green and red together. Use spring clamps or radiator screw clamps to hold the hoses on so they won't seep. I don't think the hose is long enough to go from the driver side of the heater valve to the heater core pipe coming out if the firewall.
To Elimate the core nipple blue and red together.
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If I nipple green and red together, there will be water flow...right? If so, that is what I am trying to eliminate because a/c tech said the heater control valve was bad and therefore, hot water was flowing into heater core and my ac was not as cold as could be. But, if I nipple blue and red together as you also suggest, that would eliminate the heater core right? and doing this will stop hot water flow to heater core? If So, to do this, I disconnect blue from the pipe coming out of firewall and do I cover the exposed hole on the pipe from the firewall where blue pipe was with some sort of plug and also a plug to cover the exposed hole on the HCV where the red pipe was?
These are probably dumb questions but I know nothing of this sort of thing so I apologize.
brillo_76
Elite Member
Your getting it. If you want no heater core you do the 2nd one I stated.
The first one just bypass the heater valve. So your heater core would have antifreeze flowing through it this way
Yes I tried to PM and your not able to do that yet..
Very common for new members..
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