I want to put my heating system back together. So I got the heater core, and some heater hose. But shouldnt there be a valve or vacuum operated valve that stops the flow of radiator fluid to hte heater core? If so, what is it called?

 

heater control valev , its plastic , paddock sells a metal one .

 

Depending on the year some engine flow hot coolant throught the heater core all the time.
Either way you have to run some kind of bypass that bypasses coolant all the time.

 

I took my heater diverter valve out - hated that fugly thing! I just let it flow through all the time. No need to have one really - only downfall is slightly warmer cabin temps in the summer - but with the T-tops out, I never notice!

 

Great. Thanks bro. Gonna get get one soon..

 

does any one have a picture of where and how they have they're heater control valve hooked up in the engine bay?

 

I also would like a picture to show where the vaccum line from heater diverter valve also connectsto my self. my heater diverter valve was busted and leakin on my manifold and smoking and i went to oreillys to change it over and the vaccum lines from that and some other part under my car the lines were dryrotted and hard.

 

chevy86 let me know if u find out where these vaccum lines connect to.

 

will do Daapunk.

 

The vacuum line for the heater diverter valve comes out of the firewall on the pass side between the engine block and the heater box - there will be several wires coming through the firewall along with two vacuum lines - one line goes to the vacuum port (sends vacuum to the controller in the car), the other line comes out of the controller in the car and runs to the diverter valve. As the selector slide is moved towards "warm", it allows more vacuum to be sent to the diverter valve and thus it opens farther, letting more hot coolant to circulate through the heater core.

 

dam what up camaronewbie thanks alot for posting this reply this crap has been pissin me off. im gonna try to check my car out some more tomarrow its soo blameing cold down here. ok about vaccum lines, mine were so rotted i removed my air cleaner and that one underneath it broke and the one off the plastic pieace coming off the air filter i guess its a intake sensor or something, well it is missin to!!! crap is just poppin off man, rediculous.

 

Okay. now it makes sense. On my IROC, in the wiring harness, there is only one vac. line sticking out. should I open up the dash board and run out another line for the diverter valve? Or is the Vac. line hidden somewhere else? Can you provide a picture of your set up?

 

Sorry - car is at the painter now, so can't get you a pic. If you are retaining the A/C - then maybe I'd bother with making the diverter valve work. But if no plans for having A/C, I'd yank that sucker out - to me it's more junk under the hood to be bothered with.

But - before I'd go tearing into the dash, try opening up the harness that runs through the firewall between the motor and the heater box (pass side), and see if there isn't enough of the hardline still hidden in there to add vacuum tubing onto - that would be easier than tearing into the dash.

 

hey camaronewbie me and this guy both are having problems and lucky people like u are thinkful enough to spend ur time and help man. so here i go with another question myself. between u and some other help im getting close to knowing what to do. i found the harness going into firewall and one end goes to the heater valve correct and where does the other vaccum line coming out the same wireharness coming from the firewall go? Question 2. What is the solenoid or plug type thing on the left side of engine bay that had a vaccum line hooked to, do u know where that vaccum line goes? Question 3 is on my air cleaner at the bottom of the metal air bowl is vacum hook ups, i heard they go on the vaccum nibble on my intake? is this right? LAST QUESTION. On my intake snorkle is a circle metal sensor of some sort... the vaccum line is missin from there too!!! I seem like im asking too much guys but i need the help. thanks again camaro!!

 

1) Originally I don't remember where the other end runs exactly, but - it needs to connect into the vacuum line that goes to the vacuum ball, usually under the driver side headlight. This "ball" is a factory vacuum canister to hold vacuum so that when the heater controls are changed during a no vacuum period, there is still a vacuum source to enable the controls. The ball is actually a cool design, since it would take a ton of vacuum to collapse a ball shape from the inside.

2) If what you are talking about is mounted high on the cowl lip close to the heater box, and also has a 3-4 wire connector on it, kinda flat and about the size of a pack of smokes - that was MAP sensor on a TBI car - not sure what it would be if we're talking TPI or OEM carbed car. Post a question in either TBI or TPI forums for what vacuum line from where gets connected to it - the MAP sensor senses Manifold Atmospheric Pressure and adjusts engine management accordingly - exactly what MAP is and how it's results change engine management is beyond my feeble brain.

3) I think this would be the IAT sensor that you describe - again, it's been a long time and my car is far from stock anymore. Search IAT and see if that brings info to help with that one.

4) This is the Thermac device. It's purpose is to open via vacuum when the engine is cold, allowing warm air off the exhaust manifolds to be inserted into the air cleaner assembly to help the car start and idle when air temps are cold - under the arm for the air cleaner assembly there would be a hole about the size of a old dollar coin, and a aluminum looking flexible tube (called a heat riser) that runs off the exhaust manifold up to this hole in the air cleaner assembly arm. Vacuum opens a flap in the arm, allowing the heat rising up the riser tube to get induced into the intake as warmer air is easier to swallow (for all of us, including our engines) than cold cold air. Thus I always found it funny that they called them "cold air intakes" - truly cold air is "harder to swallow" for the engine than warm - but I understand that cooler air suspends gas vapor better than hot air - I guess "cold air intake" was better sounding than "cool air intake".

Most of us that removed stock air cleaner for open element jobs no longer use IAT's or Thermacs at all - some retained the IAT sensor as most all open element air cleaner assemblies have a cutout that can be removed to install it.

 

1986 V8 cars didn't use a diverter valve.

 

Ohhhhh! So then it just runs hot radiator fluid at all times through the heater core? If so, then what controls the the flow of radiator fluid when I where to switch on the A.C.? You see, my issue is that Im going to install the original A.C. unit (which was deleted before I bought the IROC).

 

The coolant runs through the heatercore full time. When you switch from HOT to COLD a door in the heaterbox closes and the air flow doesn't pass over the heatercore. 87 was the first year for the vacuum operated valve that most thirdgen owners are familar with.

 

Sweeeeeet. Thanks for the info man. You got straight to the point.. Thanks. Peace.

 

Well, that explains why I only have 1 vacuum line sticking out of the wiring harness. My 86 was designed to flaw constantly. So now I dont have to spend any money. Cool huh. Sorry daapunk. Start your own thread on your issue with the vacuum line. That way all posts will be concentrated on you. Good luck bro. Peace.