johnnychrome

I have a 97 Cherokee sport and the heat works but not hot not sure what the perfect operating temp is for the jeep and can't decide where to start thermostat ? Any help would be great.

opake

Start with the basics, if you have a temp gauge, make sure you're reading in the normal range. Also, make sure you're coolant level is full, low coolant could cause poor heat. For the thermostat, i'd stick with a stock thermostat (192 I believe) to keep the heat nice and toasty. I recently had a coolant flush done at a shop, and getting all the old rusty fluid out of the system actually helped out with my heat some as well, though its still far from stellar. Hope this helps!

ct67_72

cherokees are notoriously bad for having dirty cooling systems.
The info above is great and the perfect start.
The problem will probably come out to be that the heater core is restricted. a coolant flush may help, but you will probably have to remove the heater hoses and backflush the heater core, and wash out all the junk.