engine heats but heater core does not
#1
engine heats but heater core does not
hey i have a 91 four runner i got that was sitting for about 3 years not running and its not getting heat to the heater core unless i rev it to about 4k nd its intermidiate burst of heat it is not constant i am getting ready to change out the thermostat tomarrow have rad flush and kit to try to get some of the rust out is there any valves or any thing i should be aware of ?
#2
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I dont particularly know the answer to your question but I have read on another thread where guys with the same problem were taking the heater hoses loose at the firewall and hooking the water hose in there to blow out the rust. It worked for them.
#4
thanks ima have to try flushing it straight with a hose or replacing it nd does the fluid HAVE to be the red toyota to heat the heater core ? ive got straight water and super flush in there now gotta pull it out tonight had a warm might here in alaska tonight its supost to freeze bought a new thermostat ima throw in b4 i change to antifreeze
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Make sure you read the directions on the super flush. Youre supposed to run the engine with heater on full speed for a certain number of minutes. Engine has to run a while to insure the thermostat opens up and circulates the flush chemical.
You dont have to use a red toyota anti freeze.
Make SURE when you put anti freeze in it that you get the engine warm enough to open the thermostat open so antifreeze can circulate into your engine block.
You may have already know this but I want to make sure your block doesnt freeze tonight!
You dont have to use a red toyota anti freeze.
Make SURE when you put anti freeze in it that you get the engine warm enough to open the thermostat open so antifreeze can circulate into your engine block.
You may have already know this but I want to make sure your block doesnt freeze tonight!
#6
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you can try a flush; I did it to my 91 pickup, and it worked FANTASTIC! all kinds of nasty junk came out, and afterward the heater worked great!
but a week later, the heater core sprung a leak; just a warning...
but a week later, the heater core sprung a leak; just a warning...
#7
Hey! So i have been fixing up a little truck for a few months now. Got a great deal on it because all the drive-train and engine is just about new. Unfortunately, everything else needs MAD work.
I have recently added new sparks, cables and checked hoses. I popped in a new thermostat two days ago and did a coolant swap. BUT MY HEATER WASNT WORKING!
So, tried the heater core flush. It worked great! I still cant get my idle right but the heater is amazing. Heads up when you do this. The pressure needed to get a big blockage out is pretty hefty and you want to realllly gradually up the pressure till it comes loose. otherwise you can damage the heater core and no-one likes taking apart the dash to replace those things.
i set mine up like this (picture) and slowly upped the pressure till it broke the nasty black muddy clock free. kept upping the pressure till the hose was full tilt, then turned it off, connected the hose to compressed air and blew all the water out. Connected the hose to water again and did the same process. ANOTHER chunk came flying out.
Hope you get the thing working. It was way easier to flush the core than i thought it would be.
I have recently added new sparks, cables and checked hoses. I popped in a new thermostat two days ago and did a coolant swap. BUT MY HEATER WASNT WORKING!
So, tried the heater core flush. It worked great! I still cant get my idle right but the heater is amazing. Heads up when you do this. The pressure needed to get a big blockage out is pretty hefty and you want to realllly gradually up the pressure till it comes loose. otherwise you can damage the heater core and no-one likes taking apart the dash to replace those things.
i set mine up like this (picture) and slowly upped the pressure till it broke the nasty black muddy clock free. kept upping the pressure till the hose was full tilt, then turned it off, connected the hose to compressed air and blew all the water out. Connected the hose to water again and did the same process. ANOTHER chunk came flying out.
Hope you get the thing working. It was way easier to flush the core than i thought it would be.
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#8
Hey! So i have been fixing up a little truck for a few months now. Got a great deal on it because all the drive-train and engine is just about new. Unfortunately, everything else needs MAD work.
I have recently added new sparks, cables and checked hoses. I popped in a new thermostat two days ago and did a coolant swap. BUT MY HEATER WASNT WORKING!
So, tried the heater core flush. It worked great! I still cant get my idle right but the heater is amazing. Heads up when you do this. The pressure needed to get a big blockage out is pretty hefty and you want to realllly gradually up the pressure till it comes loose. otherwise you can damage the heater core and no-one likes taking apart the dash to replace those things.
i set mine up like this (picture) and slowly upped the pressure till it broke the nasty black muddy clock free. kept upping the pressure till the hose was full tilt, then turned it off, connected the hose to compressed air and blew all the water out. Connected the hose to water again and did the same process. ANOTHER chunk came flying out.
Hope you get the thing working. It was way easier to flush the core than i thought it would be.
I have recently added new sparks, cables and checked hoses. I popped in a new thermostat two days ago and did a coolant swap. BUT MY HEATER WASNT WORKING!
So, tried the heater core flush. It worked great! I still cant get my idle right but the heater is amazing. Heads up when you do this. The pressure needed to get a big blockage out is pretty hefty and you want to realllly gradually up the pressure till it comes loose. otherwise you can damage the heater core and no-one likes taking apart the dash to replace those things.
i set mine up like this (picture) and slowly upped the pressure till it broke the nasty black muddy clock free. kept upping the pressure till the hose was full tilt, then turned it off, connected the hose to compressed air and blew all the water out. Connected the hose to water again and did the same process. ANOTHER chunk came flying out.
Hope you get the thing working. It was way easier to flush the core than i thought it would be.
#9
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Hey! So i have been fixing up a little truck for a few months now. Got a great deal on it because all the drive-train and engine is just about new. Unfortunately, everything else needs MAD work.
I have recently added new sparks, cables and checked hoses. I popped in a new thermostat two days ago and did a coolant swap. BUT MY HEATER WASNT WORKING!
So, tried the heater core flush. It worked great! I still cant get my idle right but the heater is amazing. Heads up when you do this. The pressure needed to get a big blockage out is pretty hefty and you want to realllly gradually up the pressure till it comes loose. otherwise you can damage the heater core and no-one likes taking apart the dash to replace those things.
i set mine up like this (picture) and slowly upped the pressure till it broke the nasty black muddy clock free. kept upping the pressure till the hose was full tilt, then turned it off, connected the hose to compressed air and blew all the water out. Connected the hose to water again and did the same process. ANOTHER chunk came flying out.
Hope you get the thing working. It was way easier to flush the core than i thought it would be.
I have recently added new sparks, cables and checked hoses. I popped in a new thermostat two days ago and did a coolant swap. BUT MY HEATER WASNT WORKING!
So, tried the heater core flush. It worked great! I still cant get my idle right but the heater is amazing. Heads up when you do this. The pressure needed to get a big blockage out is pretty hefty and you want to realllly gradually up the pressure till it comes loose. otherwise you can damage the heater core and no-one likes taking apart the dash to replace those things.
i set mine up like this (picture) and slowly upped the pressure till it broke the nasty black muddy clock free. kept upping the pressure till the hose was full tilt, then turned it off, connected the hose to compressed air and blew all the water out. Connected the hose to water again and did the same process. ANOTHER chunk came flying out.
Hope you get the thing working. It was way easier to flush the core than i thought it would be.
This is exactly what I needed! Thanks for the info and pics to help illustrate on how to do this flush! Hope that this will work for me too!
Last edited by 4runner_guy; 11-25-2010 at 08:53 AM.
#10
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A few suggestions:
- Low coolant. Air bubble goes to the highest point in the coolant system (aka the heater core) and sits there.
Check the coolant level when your engine is stone cold.
- The switching valve can freeze sometimes and not allow warm coolant to enter your heater core.
-Leaves and junk blocking the air flow across the heater core.
- Low coolant. Air bubble goes to the highest point in the coolant system (aka the heater core) and sits there.
Check the coolant level when your engine is stone cold.
- The switching valve can freeze sometimes and not allow warm coolant to enter your heater core.
-Leaves and junk blocking the air flow across the heater core.
#11
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A few suggestions:
- Low coolant. Air bubble goes to the highest point in the coolant system (aka the heater core) and sits there.
Check the coolant level when your engine is stone cold.
- The switching valve can freeze sometimes and not allow warm coolant to enter your heater core.
-Leaves and junk blocking the air flow across the heater core.
- Low coolant. Air bubble goes to the highest point in the coolant system (aka the heater core) and sits there.
Check the coolant level when your engine is stone cold.
- The switching valve can freeze sometimes and not allow warm coolant to enter your heater core.
-Leaves and junk blocking the air flow across the heater core.
Where is the "switching valve" located?
#12
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Oh, I now know where that is. Mine does open and close (Cold, the valve opens, pulling out to the engine, Hot, pulling in towards the firewall.) It seems to be working, but still get no heat after doing the flush....? Although, I did get a massive flood in the cabin where the passenger side is...
#16
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Replaced the heater core on my 4runner only to break the lever for the cold/warm lever! Damn. So I can't even tell if the heat is working or not...so many hours spent into fixing this to fix another problem. Crossing my fingers hoping it'll work after I replace the climate control, which means taking the whole dash apart....this blows.
#17
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*Update* I ended up fixing the climate control; a small plastic clip came off while I was switching the lever from cold to warm. Placed the plastic clip back and all was good. I started the truck back up and fired the heater...after a minute or two (since the truck was cold still) I finally got heat! After 10-12 minutes, the heater was fairly warm, not hot though, but I can deal with that. No more fogged up windshield in the morning plus the girlfriend appreciates the truck more since it now warms her up which is awesome.
#18
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yeah I've got the same problem in my 86 runner.
I found the switching valve, but it doesn't want to move even when I try to move it manually. My warm/cold switch doesn't work (it's loose but sometimes it wants to catch on something).
I think my switching valve is frozen up...what's the easiest way to fix it? Or does it have to be replaced?
I found the switching valve, but it doesn't want to move even when I try to move it manually. My warm/cold switch doesn't work (it's loose but sometimes it wants to catch on something).
I think my switching valve is frozen up...what's the easiest way to fix it? Or does it have to be replaced?
#19
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yeah I've got the same problem in my 86 runner.
I found the switching valve, but it doesn't want to move even when I try to move it manually. My warm/cold switch doesn't work (it's loose but sometimes it wants to catch on something).
I think my switching valve is frozen up...what's the easiest way to fix it? Or does it have to be replaced?
I found the switching valve, but it doesn't want to move even when I try to move it manually. My warm/cold switch doesn't work (it's loose but sometimes it wants to catch on something).
I think my switching valve is frozen up...what's the easiest way to fix it? Or does it have to be replaced?
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