Outer Limits 4x4 Board

hey can anyone pls tell me if the heater in a sierra is warm air that comes from the engine through the two hoses comming in from the firewall ( like most cars) or is there an actual heater box thingy that heats and blows air? this is what i was told but it doesnt sound right to me.

hot water runs through a small rad in the car and the fan pushes out hot air

if your wondering why its not blowing hot air throught the front of the dash, Its because it dosent! take a look at the colours around the heater and placement instrument panel, notice its only blue when facing you, only heats your feet and the windscreen

gumtree wrote:hey can anyone pls tell me if the heater in a sierra is warm air that comes from the engine through the two hoses comming in from the firewall ( like most cars) .

Like most cars???? what the!!!!!

I have heard of some small cars in the colder countries running porcelain heater cores!
Dont quote me on that though

gumtree wrote:hey can anyone pls tell me if the heater in a sierra is warm air that comes from the engine through the two hoses comming in from the firewall ( like most cars) or is there an actual heater box thingy that heats and blows air? this is what i was told but it doesnt sound right to me.

did you own a 65 vw bettle

Danzo wrote:if your wondering why its not blowing hot air throught the front of the dash, Its because it dosent! take a look at the colours around the heater and placement instrument panel, notice its only blue when facing you, only heats your feet and the windscreen

Yep, that one had me stumped for a week or so. Then I realised it's such a good setup as it heats the cabin perfectly without burning your eyes/making you drowsy.

Mine works awesome after I did the iZook heater clean trick!

http://www.izook.com/tech/samurai/body/ ... rclean.htm

Propably not relevant, but i just now finished fitting dash back in zook from completely removing heater core and cleaning everything. It was so full of mud that no air was flowing at all, and all the drains were blocked.
Well worth doing if youre heater is lethargic. Not that hard a job either.

Danzo wrote:if your wondering why its not blowing hot air throught the front of the dash, Its because it dosent! take a look at the colours around the heater and placement instrument panel, notice its only blue when facing you, only heats your feet and the windscreen

mate....
read the question. i know in what position u get hot air and thats not what i was asking.

gman79au wrote:

gumtree wrote:hey can anyone pls tell me if the heater in a sierra is warm air that comes from the engine through the two hoses comming in from the firewall ( like most cars) .

Like most cars???? what the!!!!!

im still learning but u also didnt answer my question, instead u just put a rude remark down. what r the 2 hoses for? do they take in hot air?

4130warrior wrote:

Danzo wrote:if your wondering why its not blowing hot air throught the front of the dash, Its because it dosent! take a look at the colours around the heater and placement instrument panel, notice its only blue when facing you, only heats your feet and the windscreen

Yep, that one had me stumped for a week or so. Then I realised it's such a good setup as it heats the cabin perfectly without burning your eyes/making you drowsy.

Mine works awesome after I did the iZook heater clean trick!

http://www.izook.com/tech/samurai/body/ ... rclean.htm

yep that looks very helpful and might just do the trick. thanks heaps for that.

Gumtree dont take it to heart, was only a light hearted poke i think.

Anyway to answer you in full, the two copper tubes that come thru the firewall have hot coolant flowing through them when the engine is hot. This coolant flows through a mini radiator inside youre dash. Then a blower fan blows air through this radiator which heats up the air, and then is directed to either youre feet or the windscreen.
The main reason why no hot air comes out the vents, is cos there is very limited space behind the dash and there would be no more room to run extra hoses to direct hot air.

PJ.zook wrote:Propably not relevant, but i just now finished fitting dash back in zook from completely removing heater core and cleaning everything. It was so full of mud that no air was flowing at all, and all the drains were blocked.
Well worth doing if youre heater is lethargic. Not that hard a job either.

is that what 4130warroir also did. if so i think some cleaning is what i need to get some hot air going again.

PJ.zook wrote:Gumtree dont take it to heart, was only a light hearted poke i think.

Anyway to answer you in full, the two copper tubes that come thru the firewall have hot coolant flowing through them when the engine is hot. This coolant flows through a mini radiator inside youre dash. Then a blower fan blows air through this radiator which heats up the air, and then is directed to either youre feet or the windscreen.
The main reason why no hot air comes out the vents, is cos there is very limited space behind the dash and there would be no more room to run extra hoses to direct hot air.

yep that all make sense to me now. now that i understand how it works it will make it so much easier.

gumtree wrote:is that what 4130warroir also did. if so i think some cleaning is what i need to get some hot air going again.

No from teh sound of it he just drilled the hole and blew it all out, which would work if its just leaves, but i hate doing things twice so i stripped it completely the first time so i know it works.
Drilling the hole would not have worked with mine anyway, the mud was caked in there so hard that it required a fair amount of time with the air blower and a pick getting it all out of the fins.

gumtree we are all just having a poke but really I'm not sure were you would get the idea that the amount of air that comes out of the vents would travel through the pipes and you looked at where they go into the fire wall did you look at where the other ends go??? seriously a little bit of common scene would have told you the air doesn't come from the heater pipes. alittle more poking around and hey you'll than learn how crazy your question is, but hey yes we all learn in one way or another the first time i pulled a free wheeling hub apart it took a good day to learn it only goes back together the way it came apart.

yeah im going to have a good poke around 2moro hopefully if not the weekend. hopefully it doesnt take me too long to do.

PJ.zook wrote:Gumtree dont take it to heart, was only a light hearted poke i think.

Thanks Pj. although it wasnt a poke at all Some people dont know about some things like this, Sorry Gum Tree if I offended didnt meen it, I have been asked the same Q? 4 times before, about why it dosent blow hot air through the front, I know wha your Question was and as far as I could see Boner had answered it,

hot water runs through a small rad in the car and the fan pushes out hot air

Sorry for the misunderstanding,

Ps: Nice link 4130 Warrior

Danzo wrote:

PJ.zook wrote:Gumtree dont take it to heart, was only a light hearted poke i think.

Thanks Pj. although it wasnt a poke at all Some people dont know about some things like this, Sorry Gum Tree if I offended didnt meen it, I have been asked the same Q? 4 times before, about why it dosent blow hot air through the front, I know wha your Question was and as far as I could see Boner had answered it,

hot water runs through a small rad in the car and the fan pushes out hot air

Sorry for the misunderstanding,

Ps: Nice link 4130 Warrior

thats cool mate, its a bit hard to tell what ppl r actually saying though a computer screen but it seemed that the first few posts were making fun coz i didnt know how it worked. i can see how ppl can mistake that the hot air doesnt come through the front vents only where the red arrows show. sorry for reading the message wrong buddy

my heater box has a small hole in it as off last weekend and dripp's water on your feet as you drive. theirs another way to keep your feet warm.

I also found when doing alot of mud and revving the engine when the temp goes up a little I turn the heater on to help take some of the heat away sorta like a extra radiator....

Who ever owned my Sierra previously or sometime through its years I think it lived under a pine tree because the heater box was filled with pine needles an small leaves, I actually had to add a bit of a bottle neck into mine to fit the head unit in with the cables coming out the back it was a tight squeeze...

lexplay wrote:my heater box has a small hole in it as off last weekend and dripp's water on your feet as you drive. theirs another way to keep your feet warm.

Either way thats not a good thing, if its green water its even worse lol

MUD-PIGSIERRA wrote:I also found when doing alot of mud and revving the engine when the temp goes up a little I turn the heater on to help take some of the heat away sorta like a extra radiator....

I had the same problem but slightly worse after instaling my 1.6,
Got a little worried there for a bit,
Took the radiator its self to red devil radiators, Got them to do a strip and flush and new paint= $88
It was 80% blocked maybe you should do the same Mud-Pig,
If its over heating it shouldnt be your heater core

gumtree wrote:hey can anyone pls tell me if the heater in a sierra is warm air that comes from the engine through the two hoses comming in from the firewall ( like most cars) or is there an actual heater box thingy that heats and blows air? this is what i was told but it doesnt sound right to me.

'
To actually answer your question,

Engine water/coolant comes through those two pipes through the firewall to a heater core. Air is blown across the hot core to create the heat coming out of the vents. Basically its another radiator but inside the car.

Leaks in sierra heatercores arent uncommon so just find someone who can maybe silver soldier, find leak, plug it and put back in.
Mine isnt immune, mine leaks unfortunately after putting back in. I just thought then, dont know if this will work but ill try, our mains pressure here is pretty good, so i might try hoseclamping the end of a garden hose to one side of core, then another shorter bit of hose to the other, then turn water on and see where leak is, if it doesnt appear then, start restricting the outlet hose and see what happens.

Well i took my dash apart...again, and disasembled the heaterbox...again, and found it wasnt the core leaking, it was just the clamps that hold the rubber hose on didnt go tight enough, and the coolant pressure was squirting coolant past the bloody firewall grommet and into back of heaterbox, then down onto floor in a green puddle. So heaterbox back in, dash back in, 2hours later im back where i started.

Lol, i hate when that happens. all that work for nothing. i did the hole in the plastic thing warroir4130 said. there were leaves and a few cigarette buts down there. 2moro im gonna gurni all the dust and shit on the inside of the dash as the front half of it is off. on the weekend ill put it all back together when its all clean

Taking the dash apart is actually piss easy if you ever want to try it.
Main points to remember, is unscrew the plastic nut holding the bonnet release pull handle, located behind the glovebox. Also go along and stick youre fingers behind the dash thru glovebox hole and dash hole and release loom from those thin metal retainers. I found steering wheel needs to come off too.
The reinforcing bar behind/under the dash also needs to come out too to get the heater box out, no big deal, 8 bolts.
Also getting the heaterbox out, theres one 13mm nut in engine bay on firewall holding it in, took me about 15min of cracking teh shits till i found it.