My radiator hoses once got all bunched up and squished by the spare tire -
in part because my leaky front heater core was bypassed, so extra hoses
were dangling in the space.  You might check to ensure the spare tire does
not compress any of those hoses.

I didn't read all the replies carefully, but the old trick of turning on
all heaters at full blast can help reduce temps.  Then you can sweat with
your van as you push up those hills.

Tom
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