Can't get much heat in my work van? Any idea's?

[brads70]

Not a Mopar but figured some has " been there" I have a 86 Chev G-20 conversion van I use for my business(4.3 V-6). I just bought it this summer.  I bought a winter front for it but haven't received it yet (E-bay) I changed out the thermostat ( 195) new antifreeze, and with cardboard totally blocked off the rad. The temp gauge at best goes to half, 95% of the time it's only at 1/4. Some heat comes but not real hot. I know it's a big area to heat. After talking with some buddies that have had them they all say heat is always a problem in winter with those years. All I can think of is maybe the heater core is partially blocked? I pulled off the hoses going to it and blew air through with no problems? When looking where the heater hoses are routed one goes to the top of the rad ( ? ), the other disappears some where towards the back of the engine, I assume to the intake somewhere. With all the Chevy's I've had the heater hose always goes to the water pump. I'm wondering if I re-routed it to go to the water pump if it would give me more heat?
Any idea's...words of wisdom?
Thanks Brad

[brads70]

Just phoned a buddy and he wondered if the rad cap needs replacing? He thought maybe the system wasen't building up enough pressure ?

[Super Blue 72]

Can you get a higher temp thermostat or would that not be good?

I know on some older Honda/Acura cars the heater control valve does not open up completely due to the cable to the heater control valve needs to be adjusted.

[brads70]

I have a 195deg. in now that the highest. There are no cables going to the hoses. When the engine is warm ( as warm as it gets anyway) the heater hoses are  cooler than the rad hose?

[426HEMI]

Brad is there air in the system?  Did you just change something that could be the problem.

[brads70]

Brad is there air in the system?  Did you just change something that could be the problem.

Not that I can think of? I replaced the thermostat, when I do that I always drill an 1/8 hole of to the side to let the air escape. So I don't have to wait for it to open to add all the antifreeze..
I'm waiting for Neil to tell me to move way down south...

[Super Blue 72]

If the heater hoses are cooler than the radiator hoses that tells me there is no circulation to the heater core.  If only one hose is hot, then that would mean that the inlet hose is getting hot radiator fluid so its a plugged core or a valve issue.

So where is the mechanism that controls the flow of coolant to the core?  The should be a heater control valve, yes?  On some cars it is vacuum actuated if there is no cable.  If that is the case, make sure the vacuum hose is connected and getting vacuum.  If no vaccuum, then it might be soemthing in the heater control panel assembly. 

[426HEMI]

Is it a dual system with a heater in the rear?  I really suspect air in the system or a stopped up heater core.

[brads70]

There are no valves just 2 hoses going to the heater core. I took off the hoses and blew air through with no problems?  Only one heat source in dash nothing at the rear. I have had 3 different people tell me the heating system in these vans was "lacking" so say the least?

[Bullitt-]

Find the valve....I know nothing but I bet it's the bottom one, looks like it screws into the pump or intake.

1986 CHEVROLET G20 VAN 4.3L 262cid V6 4BBL (N) : Heat & Air Conditioning : Heater Control Valve
FOUR SEASONS Part # 74612 More Info
Front
   
Part Image
   $11.71   $0.00   $11.71   
Add to Cart



CDELCO Part # 155372 More Info  {#22532158}
VALVE,HTR WAT FLOW CONT 16MM, ONE DIRECTION FLOW VALVE
   
Part Image
   $8.61   $0.00   $8.61   
Add to Cart

[brads70]

Thanks Wade I'll have a look! Bottom one just looks like a nipple! Maybe that's the problem!

[Bullitt-]

That top picture looks like it may be vacuum controlled..... When you get that figured out maybe you could tell me how to get my JohnDeere/Kawasaki push mower to run right.. high idle no torque. 

[72rtchallenger]

if the vacuum controller is not switching from cool to hot then it will not put out heat properly

[brads70]

That top picture looks like it may be vacuum controlled..... When you get that figured out maybe you could tell me how to get my JohnDeere/Kawasaki push mower to run right.. high idle no torque. 

Hi Wade,
 Just went out and looked  ( burrr man it's cold outside!) The top one is not on my van for sure, the second sure looks just like a hose nipple? But it does say a one way valve? I might have that screwed on the intake where the one hose goes to? The other hose goes to the rad and it's got plastic tanks with the hose nipple molded in.
  still stumped?
About your mower... what does it do, stall when cutting grass? How does the air filter look? It DOES have high idle? Is it 2 stroke  or 4 stroke? Don't see to many of them up here ( expencive)

[brads70]

if the vacuum controller is not switching from cool to hot then it will not put out heat properly

I assume that is an under the dash thing?