no heat at all comes out no matter what setting the knobs are on. it only seems to get warm when im out driving for hours! i only have a 15 minute drive to my classes in the morning and it used to heat up maybe halfway but now it doesnt. i replaced the thermostat. could that be the problem? or my radiator? i have no clue in this department guys. i heard there is a valve somewhere that controls the hot water to my heater core? and its not letting the heater core get warm? any ideas? i havnt really tinkered with anything else besides the thermostat that would cause this.

 

The valve should be on or near the firewall, where the heater hoses go through. It'll have a wire connected that controls the amount of water. The other end of the wire goes to the temp control on the dash. Get someone to move the temp control and see if the wire moves.

Another possibility is a plugged heater core.

 

on or near the firewall under the hood or under the dash?

does that wire go behind my speedometer and junk and plug in there?

 

Under the hood, and the wire should go to the temp control lever on the heater panel

 

Yep, top of the firewall on the engine side (has the red circle in the picture below):

 

thanks 4crawler but im having a hard time locating that on my truck. here are a few shots i took (sorry for the crudity but i took them with my phone)
of my engine compartment. i think i found what you were talking about. i found 2 hoses that go through my fire wall but along them they have numerous hose clamps and valves. you can see it going through the firewall on the left side of the picture:

top of the hose:


bottom of the hose:


there are a few things to tinker with along this hose. is this the right hose? is the hose im looking for supposed to come off the radiator?

 

The heater core should be inside the cab. Hoses must go through the firewall to get to the heater core. Might try backflushing the lines to make sure the core is not clogged up and that the valves allow coolant to flow. Yours looks different than mine, but that is probably the right lines.

 

are you fuel injected? that might be why it looks different. anyways, what do you mean by backflushing? finding my heater core and forcing water the other direction? or unplugging that hose and force water in the correct direction.

 

Yes, 22RE:
- http://www.4crawler.com/4Runner.shtml#Engine
Flushing is running water through the heater core in the forward (normal flow) direction. Back flushing is flushing in the reverse flow direction, i.e. push water in the outlet and let it run out the inlet (and valve). Why? You have big tubes into the core were a bunch of small passages split off to spread the coolant out over a larger surface area. If any are plugged, forward flushing will just force any blockage farther inside the core. Backflushing can help to force any clogs back out of the core and into the larger inlet tube. I got lots of crud backflushed out of mine when I first did it. I repeated back-forward-back-forward until the water ran clear. I just shove a tapered garden hose nozzle inside the rubber hose to make a tight fit. Then squeeze open the nozzle and let the water flow.

 

sweet, thanks alot man. i'll have to try that after class tommorow. now all i have to do is figure out which hose is in and which is out. i wouldnt be suprised if a huge chunk of mud flew out of the end after i flush it out

 

choo choo!

 

its cold in chino hills?!?!?!

hehe, just had to throw that in. hope you get it fixed

Bob

 

haha it's cold in the mornings here man! then even colder in your truck covered in mildew at 6am!!! especially this time of year. besides, not having a heater just bites the chode in general

 

haha, yup. it feels like a giant refrigerator. i keep my snowboard gloves in my truck for that seemly long, cold drive to class early in the morning

 

check your blower, its under the dash

 

its blowing air, its just air from outside. if its hot outside i get hot air. if its cold outside i get cold air. if only i could have the opposite i would be set

 

Did you happen to see this thread? This was the exact problem I had as I was leaving on my 9 hour drive over 2 colorado passes to Farmington last week...

https://www.yotatech.com/forums/f2/sounds-behind-dashboard-76827/


Brrrrr.... it was a cold drive. Thankfully TC figured out that we could turn on the rear heater (2nd gen 4 runner) so it made it a little better. I still haven't dug around to see if it is a fuse or an actual blower that went out. (The heater core is fine since it blows hot air into the rear of my 4 runner)

Just thought this might help.

 

yea, well it blows in into my pickup but like i said before its nothing special just air from out side. and if i put it on recurclate its just air from inside. all the finctions work like defrost and that stuff. and i notice it getting slightly warm when i move the knob to hot. but its not like it used to be. its not that warm either. nohting to warm up the cab just to warm my fingers for a few seconds.

 

Have you backflushed the heater core and checked that the heater valve is working OK?

 

Pickup and 4Runner heater hoses will look a little different because the pickup does not have lines that run back to the rear heater. 4Crawler hit it I think, check the control line that comes out of the firewall (in the first pic its the little blue thingy at the lower left of the red circle). This same thing happened to mine some time ago and that was the cause. Also, it may sound a little obvious, but is your engine coolant full? If not, you could have an air pocket in the core.