Heater Core Shutoff?

[motormayhem]

Is there supposed to be some sort of valve that shuts flow off through the heater core when the control is on cold? I seems like a lot of water bypassing the radiator that could be cooled. I tested it yesterday and when it is 112* outside the truck ran at 205 with heater off and 195-200 with it on.

 

[Warthog]

Th heater core continuosly has water flowing thru it. The only control is the air flowing across it.

I guess you could install a manual shutoff. I've done it on a gasser but haven't installed one in a diesel.

 

[Midnight Rider]

Like Warthog said, the fluid isn't bypassing the radiator, it is always flowing through the entire system.

Running with the heater on will pull some heat off the motor, but of course you will be cooking yourself in the cab. I used to have to do that when I had thermostat problems in my Mustang.

You would need more than 1 shutoff to stop fluid from flowing through the heater core anyway. I would think that only stopping the flow from one direction would still leave some fluid in the heater core.

 

[Ken_86gt]

Be careful about adding a shut off valve to the heater core if it didn't come with one stock. On many engines the flow to the heater core is required for the thermostat to operate properly. If you really want to stop the heat getting to the heater core a bypass setup would be fine.

 

[Oldsouthernboy]

Check LMC for a water valve, It is installed in an ac unit, you can control it buy a installing a cable assy, to open and close the water valve. Kinda like the vent at your feet.