Stupid V8 question....

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1Fine40

1Fine40

Rust Buster
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So, It has gotten colder here, and I have no heat!! Was wondering if maybe I did not hook up the heater lines correctly from my v8 to my heater valve...It's a 78 VJ40, and I took the line coming from the manifold and ran it to the inlet on the heater control valve. The return line from the heaters goes to the top of the WP. Is that right?? If so, I may have a wad of gunk clogging the heater lines?? Ideas to check out?
Thanks and Cheers!
 
65-fj45 said:
You could possibly have an air pocket in the heater. this would cause the water not to circulate. try bleeding the system.
Click to expand...

O.K., second dumb question for the day, How does one do that?? Thanks for the idea BTW!
 
Would like to hear this also...just finished re-connecting all the heater lines and have essentially a dry system now...what's the correct procedure to fill and prime the coolant/heater system from dry?

thanks
 
when mine was dry I just parked it on an incline with the radiator being the highest point (allowing air to escape), and then filled the rad and let it idle with the heater on, and continued filling the rad until it stayed at a constant level. It may surge and spill over, don't get antsy just let it do its thing and run its course.

Took me around a week of driving to get it completely back to normal-just kept checking and refilling. Having an overflow bottle would help.
 
It may help to park the truck on a slope so the radiator is as high as possible.. then pull the cap and fill her up.. start it and if you have an air leak it should work its way to the top (or the radiator).. you could also squeze the lines to help pump out the air and pump in the water..
 
Hmmm, I can give it a try at lunch time...I'll let ya'll know what pops up or out!
 
There were lots of bubbles coming out of the radiator neck, and lots of coolant, which I caught with an empty water bottle from the overflow tube...I let it run for 45 minutes until the temp was 180 or so. But, the heater still blows cold air! :( What the heck??
The rear heater lines do not feel real hot either....Guess I'll be pulling the whole mess apart real soon... Must be blockage somewhere in there.....

Cheers
 
disconnect the top hose to the radiator and see if you can get anymore air out of the system, the radiator fill cap doesn’t permit the best flow.

dose the engine run at normal temp? If it is overheating there may be an air pocket in the block as well, bad situation. If it doesn’t ever get warm, the thermostat is in question.
 
dose the engine run at normal temp? If it is overheating there may be an air pocket in the block as well, bad situation. If it doesn’t ever get warm, the thermostat is in question.[/QUOTE]

Yeah, the engine runs at normal temps, but of course with a high flow WP, it should be pretty cool when temps are low.....The T-stat is a high flow unit from Stewart...it has some small holes in it to enhance cooling....I remember when I ran without this stat, the engine got too hot and I could hear hammering in the block from the steam....took it out real quick......there is no bypass for the coolant to have a minimal flow with a SBC....or is there?? I remember the 2F had some small bypass hose on the Tstat housing to keep things from over heating in the block...does a SBC not have a provision for that??

Confused...
 
does the heat valve open???????????? just sounds like its stuck.
manually move it, just cause the pull moves inside doesnt mean its opening.
if no heat on the through side of the heater valve then bad or stuck vavle.

start simple

the way you describe is how my heater is ran. i think, to wet out.

water always pumps, just not released into the rad until therm is open. Yes a small hole in the t-stat is a great idea, and prevents air pockets. THIS is why i lean more towards faulty heat vavle.


open heater vavle, pour in equal wat to anti, say 1 of each, start, run, finish filling, make sure you have heat. YOUR DONE. clean up enough to go drive, and job well done.

done this too many times.
 
HI^C is right - the water should always be pumping. Sounds like the valve or a blockage in the heater core or hose. Disconnect the heater lines and make sure they are open and flowing free.

The waterpump pressurizes the block. Water will come out of the fitting on the intake manifold rather the t-stat is open or not. It goes through the heater loop and returns to the waterpump.
 
One way to see if your heater core or valve are plugged is to undo both heater hoses, and put your garden hose to one side, then the other (to simulate the engine water flow). If nothing flows through, something is plugging it up. Sometimes by alternating from one hose to the other you can knock some of the crap out of a plugged core.

What year is the V8? Chevy I assume? Yours is plumbed like mine is and I have plenty of heat.
 
Heh, well you guys called it pretty well! Last night, I took the unit into the garage for a check out, and at first nothing seemed out of the ordinary. The engine temp was normal, the heater valve operated when I pulled the knob, it all looked fine, but still no heat! I was about to start pulling hoses and check for blockage, when I noticed that the metal frame on the heater valve was deformed some!!! Actually deformed a bunch! Yeah, the lever moves, but the plunger does not go up very far at all!! I removed it, straightened everything out, and now the plunger goes an extra .5" to .75" further open, and I have HEAT!!!! Woohoo! Must have bent the heater valve when I rebuilt my heads last June!! It just never got cold enough to need it til now... Thanks for the advice, it will be nice to be warm in the rig again!!

Cheers!!
 
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