heat coming out near feet with vent seclected

[hippieman9]

Ok dumb question, So I took my DeLorean for a shake down yesterday after replacing the fuel pump, and I was trying the A/C and Heat and vent modes. It was cool enough to run with the Vent on and windows open. While on the vent setting I could feel heat on the floor boards. I could also feel the cool air coming out of the vents above the radio.
I also Just noticed if I switch the climate control from off to heat the valve in the engine compartment doesn't do any thing. I assume this should move when switching between heat and vent and off?

I had to adjust the lower radiator hose because it was rubbing in the sway bar, of course I lost some coolant and I burped the system, and I had the Heat on full blast and it was barley warm.

So is the heat valve bad?
Would this cause warm air to be coming out by my feet with the vent selected?

Thanks for any input.

[Bitsyncmaster]

The vacuum valve that turns off the coolant flow to the heater only turns on when the AC is set to MAX. I had a plan to make the valve work with the temperature knob setting rather than the MAX setting but have not got around to do that yet.

[DMCMW Dave]

The vacuum valve that turns off the coolant flow to the heater only turns on when the AC is set to MAX. I had a plan to make the valve work with the temperature knob setting rather than the MAX setting but have not got around to do that yet.

The foam that goes around the heater pipes has come loose on the back of the heater box. This lets hot air out the back (its not coming out of the floor vent).

You can feel this foam insulation by reaching up over the gas pedal. You can often put it back in place with glue or well-placed duct tape. You will be doing this completely by feel though.

I did put a small medical vacuum valve on my car so that I can shut the hot water off regardless of the mode switch setting. In the factory configuration the hot water is in at all times except for MAX AC.

[hippieman9]

[QUOTE=DMCMW Dave;237030]The foam that goes around the heater pipes has come loose on the back of the heater box. This lets hot air out the back (its not coming out of the floor vent).

You can feel this foam insulation by reaching up over the gas pedal. You can often put it back in place with glue or well-placed duct tape. You will be doing this completely by feel though.

Thank you I will check this out.

[hippieman9]

OK, so it seems as if my heat valve is not functioning. I tried Max A/C then switched to vent, it didn't move. So Looks like i need to trace down the vacuum tubes to check for a broken one. This may also be why my A/C never gets super cold. because heat is being let in along with the A/C. IDK. This is all new to me to diagnose, any advice? Thanks

[David T]

Does your mode switch hiss? Is it easy to turn? It may need to be rebuilt.

[hippieman9]

Does your mode switch hiss? Is it easy to turn? It may need to be rebuilt.

no hiss, and turns fine. I can tell it opens the Vent when vent is selected, and Max A/C you can feel the A/C, just noticed warm air on my feet in Vent position and only warm air with heat selected.
I have noticed my Hot water valve doesn't move no matter what is selected, So I am wondering if that may be broken.

[DMC5180]

Their is a very small plastic vacuum line that runs across the back wall of engine bay near the bottom next to the frame cross brace. The hard plastic tube connects to rubber line that goes to the water valve. Make sure the tube and line are connected. It doesn’t take much to have them separate accidentally when working in that area.


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[hippieman9]

Their is a very small plastic vacuum line that runs across the back wall of engine bay near the bottom next to the frame cross brace. The hard plastic tube connects to rubber line that goes to the water valve. Make sure the tube and line are connected. It doesn’t take much to have them separate accidentally when working in that area.


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I found that someone who worked on the car previously had 1. put the vacuum lines in the wrong ports at the mode switch, 2. The connection to the hot water valve was not connected to the T. 3. I replaced the hard plastic line all the way to the hot water valve.

after fixing all this , they work perfect! Also I used Air shock line from a Harley Davidson for the vacuum line. slightly bigger ID but works great.

[DMC5180]

Great fix, glad you got the vacuum stuff straightened out.

As far as the hot foot goes, you will need to reattach the foam on the front side HVAC housing. Hot water always flows through the core unless the Mode Switch is set to A/C MAX. Just driving will force outside fresh air to flow into the HVAC housing and it is always trying to find a way to escape the HVAC housing, in this case the heater core foam seal around the lines.


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[hippieman9]

Great fix, glad you got the vacuum stuff straightened out.

As far as the hot foot goes, you will need to reattach the foam on the front side HVAC housing. Hot water always flows through the core unless the Mode Switch is set to A/C MAX. Just driving will force outside fresh air to flow into the HVAC housing and it is always trying to find a way to escape the HVAC housing, in this case the heater core foam seal around the lines.


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OK, Ill will look at that next. you said you can't see it from the footwell, just have to feel with my hands?