I thought he meant a normal system with coolant in it, but not circulating due to the thermostat not being opened.

In either case, blocking off the radiator in very cold weather will help heat an engine (and trans) heat up faster and maintain a good temp without significant fluctuations once at temp.

Ex: When the radiator is at a very low temp (lets say 20F) and then is hit by 180F+ coolant, that is a shock to it. Further, if the coolant is significantly cooled down, it brings down the engine temp too fast, the thermostat closes, and this cycle repeats more rapidly than with a blocked off radiator.

Also your in-Jeep heater (HVAC) works better. Tested this with my calibrated finger tips

 

I thought that also when I first read it. Then realized I had read it wrong. Thank you for letting me point this out.

Yep... absolutely. That's what we were discussing earlier in the thread. Sometimes even just the heater core is plenty enough.

 

I'm pretty sure his comment about "radiator with no coolant flowing through it" was in reference to operation before the thermostat opens, not to operation with no liquid in it at all. "No coolant flowing" would not normally indicate to me that it was empty.


I could be wrong, of course...

 

And I could also be wrong of course... lol

Just trying to give benefit of the doubt because it could have been interpreted either way. Confirmation of which way would help greatly.