Heater core coolant shut off valve

[Timinator]

6th gen mirage:

I am looking into a heater core shut off valve, I know some of my old vehicles had them, and the AC is ice cold with them closed...I posted on FB about it, but can not find evidence of the valve mentioned. I am looking to install one of these bypass valves, probably from a ford ranger, and only turn it 'on' in "winter" being I live in south west florida, I am much more desperately in need of cold, than hot haha

[Daox]

Its not a bad idea. It'll make your car warm up faster too, and that means better mileage, especially on short trips.

[Fummins]

It'd be easy enough to make your own. Just get 2 ballvalves and a couple t's.

[Top_Fuel]

Here's the inlet/outlet to the heater core on the firewall...



Maybe just get a short length of hard tubing in the shape of a "U" to connect those hoses together to completely bypass the heater core (no cutting of hoses necessary...with any luck).

I would be curious to see if this actually makes a measurable temperature difference in your AC.

[Fummins]

Measurable maybe, noticeable doubtful I'd think the heaterbox flaps do a good enough job of blocking off the heater core? But I'm still curious to see what happens.

[Timinator]

I noticed a big change in my old F350s AC (before the truck broke) by not letting the core heat up to 205°. Any heat, especially in a small vehicle AC system, is degrading the cool of the ac...im going to try this, and see what happens. Worst case I gain 5° cooling, best case I create a freezer haha

[Timinator]

I was going to use this, where the lines parallel between the intake and firewall

[Daox]

Cool. Let us know how it goes.

[gone.a]

Any updates on this old thread?

[foama]

Any updates on this old thread?

See:

https://mirageforum.com/forum/showth...-heats-the-car




The older Mirage's had a different heater assembly.
Air passing through the heater assy was heated at least 5°C over outside temperature, regardless of the heat being turned off. The flap covering the core inside the heater box was fully closed and yet the car was always being heated.
Newer Mirage's, dunno since when, have a modified heater flap, presumably because of that.

There are basically two sort of designs in cars. First type has a " hot water tap" regulating hot water going through the heater core, but this is not on our cars. Second way to do it is by an air-flap over the heater core, the core itself always being heated, just as in our cars.

Since my 2014 model has the old unmodified kind of flap inside the heater assembly, which heats even in summer, I disconnected the heater core from circulating coolant by means of a "U"-shaped piece of pipe. Coming winter it will be reconnected in order to re-enable heating.

A word of warning: Do not simply block it off, because the coolant must continue to circulate through the throttle body and other parts for example.