Odd heating situation

htfx19

Herzel Frenkel
I get a lot of (no pun intended) hot air into the cabin. It happens when the car is up to normal temp (about mid-scale) and that is after some 20 min of drive.
The hot water supply to the h/c system is cut off by extra valves I've installed on both heater tubes.
The hot air is coming like from the foot well.
Any ideas? A solution would be even better...
 
A/C car?
On mine, (non A/C) the lower slider lever controls the air input, opens a flap in the scuttle, if open, air comes into the cabin from the outside, if it's hot outside, it's hot air. Close that lever?
 
I will check but I doubt it.

Mine is an '87 A/C equipped car and heat comes in only after engine temp reaches working condition.
This suggests it is heated by passed the thermostat junction...
 
I have no idea how A/C cars are set up so ignore me. I will say that even with my heat controls to cold (valve supposedly shut, OEM valve) there's still warm air down there. I always assumed the valve wasn't closing all the way, could be the hot line going to the valve is enough to produce heat there, it's in the passenger's footwell already at that point so guess warm coolant will collect there, though it shouldn't be flowing so how warm could it get?
Just last night I was out lubing my valve. Mine gets really hard to move with the lever controls and needs a shot of lubricant to get it working smoothly again. Cold mornings and warm afternoons has me wanting control over heat. Not being able to stop hot air on hot days is annoying, no?
 
As I've mentioned,

I added valves in the engine compartment to shut all hot water to the cabin heater, yet it heats...
 
I wonder if the coolant lines running under the floor and through the space in the tunnel under the heater core is enough it introduce heat in the cabin? Maybe some insulation in that area would be wis
 
So with the valves off...

I added valves in the engine compartment to shut all hot water to the cabin heater, yet it heats...

If you turn the heater lever all the way to hot, and the fan on full, you should get only ambient temp air blasting out of the vents. That's what you have?

Pete
 
If Herzels valves are not leaking...

I wonder if the coolant lines running under the floor and through the space in the tunnel under the heater core is enough it introduce heat in the cabin? Maybe some insulation in that area would be wis

Then the only thing on those lines is ambient temp.

Edit: Provided of course the valves are back in the engine bay and not up near the heater core. I am guessing they are in the engine bay and/or the spare tire area.

Pete
 
Also Herzel... some points...

When I added A/C to my Vette I carefully and religiously managed to install the heater valve in backwards... and even with the valve shut... coolant still managed to go past it and the A/C could not overwhelm it.

Just sayin...

You have TWO sources of HEAT... the ambient air and the coolant.

1. Coolant... PROVE the coolant is not getting by the valve(s) by disconnecting ONE hose and looping it back to the engine... so that absolutely NO coolant can get up to the heater core. I think this can easily be done where you installed the two shut off valves in the engine bay.

If that doesn't solve the "mystery"... then...

2. Ambient air... make sure ALL the PLUGS and GROMMETS are installed and in place up front. Have your daughter shine a flashlight both under the front trunk to the cabin, and from the cabin (under the dash) to the front trunk... while you look for beams of light coming through. Use Duct Tape to patch up any problems.

Tell her HELLO from me...

Let us know what ya find, and stay safe my friend!
 
Good points Tony

I'll do the check (in few days.
My daughter is fine. She is teaching first and second graders and she loves it.
We do get together quite often, she only lives some 20 miles away.
I hope you are well,
Regards,
 
Thanks Herzel... we think of you two often...

Both Sharon and I are still having health issues but we always have HOPE.

Hope you find your solution easily. I've been working on my Vette's A/C unit as well and found two EASY problems, but difficult to get at. One was that infamous heater valve I spoke of earlier. The cable sheath moved in its mount so the valve neither opened or closed fully! Hopefully tomorrow I'll have it all patched up. Its been three days, 3 or 4 hours a day!
 
Other sources of heat are possible. If the heater core circuit is blocked off, there are still ways for heat to come in from the front. Ambient air as has been mentioned by a few, radiator pipes as has been mentioned.

I think that radiator air flow which travels under the car but could be finding a way in is possible. There are a few grommets and such to prevent this that may be missing, especially on A/C cars where there are more paths through the front bulkhead. This is an issue on my Scorpion especially since I've removed some of the A/C hoses and so have had to seal off the extra holes using flexible self-adhesive flashing normally used in home construction.

Another potential source that I've noticed in the summer is roadway heat, which radiates up from below and can penetrate the bottom of the car. In direct sun, nice weather, asphalt in particular can reach temps of 200ºF.

I hope you can find the source Herzel!
 
than it would be everybody's problem. But I haven't heard any complains...

If the above was referring to my comment about heat getting in from the radiator tubing running in the tunnel, then yes, you are hearing at least one other complaint, I have constant heat from the center vent with valve closed, and vent set to defrost (vents closed, still comes in) also heat by feet) I have just the stock OEM valve and it is hard to move so I have just blamed it for 4 years but I can manually close it (by crawling in the footwell) and it has no effect, so likely my valve doesn't completely close off the heater core, since it seems most people can stop the heat and everyone has radiator tubes in the same place, anyone else have heat who doesn't want it?
 
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