On 7/8/2017 8:58 PM, Vic Smith wrote:


No it's not misinformation. Anybody who's ever replaced a heater core on GM vehicles that
I know of, know that the core has an inlet and outlet and no valves restricting flow.
It's the job of the mixer door to adjust heat in the cabin. There are some vehicles that
have heater water valves, but I haven't worked on them.
And their is no "extra" heat.
Engine designers can't eliminate waste heat until they design one that's 100% efficient.


It has been probably 40 years since I played with heater cores, but I do
know there was a valve in the line to stop the flow. Maybe thing have
changed?

https://www.yourmechanic.com/article...hard-zeppetini

Google heater core valve and then click on images.

This is GM specific
https://www.google.com/search?q=heat...w=1366&bih=638