I have a 93 4runner w/160,000 miles and I was wondering if anyone
> else experiences this same problem with their 4-runner...
> Sometimes there is a lot of heat that comes up from underneath
> the center arm rest ( down where the seat buckle is bolted ). I have the
> rear seat heater option... does that run off of hot water? Or the heat could
> just be from the transmission? I've had it a while and just thought it was > nothing
> to worry about. Car runs fine, also no problems when I feel the heat coming > up?
> any ideas?
Rear heater uses hot engine coolant to operate. It has its own valve on the unit itself along witha fan switch. If you leave the valve open, you'll be circulating hot water through it all the time and get the symptoms you mention. Could also be heat from the transmission and transfer case, they get pretty hot, too.