98jeepcher

Ok i got in my 1998 jeep cherokee classic well tonight and i had already warmed up the truck to normal running temp, well i turned on the heat but it was only blowing warm air not hot as usual! fan speed changes when i turn to other speeds but heat just isnt like it was this morning this morning it would roast my eyes off if i let it! . I cant be driving my almost two year old daughter around with no heat so, any ideas and ways i could fix this would be greatly appreciated, Thanks

Abovetimberline

It worked and then next time you used it it did not correct? Your does not have a heater control valve,so it is either a plugged core or the blend door is not working right.
I would check your core for flow first.

captainwoot

low coolant?? prob plugged core as timberline suggested.

98jeepcher

yea it worked in the morning drive and later i went to drive it it just blew warm not hot like the morning.

98jeepcher

i have no clue but i will check! thanks also would changing my thermostat maybe help ive noticed my truck has been running a little warmer than usual lately?

Abovetimberline

It will help to keep the engine cooler if it is overheating,but it is not going to help your heater unless the tstat was stuck open and not allowing your engine to get up to normal temp.

98jeepcher

alright thanks man ill check out the core to see if its plugged.

XJ's~For~Life

I have this same problem kinda.

My jeep always has ran at 195 and hot heat, Never had to run the **** past 1. Now it is running past 210 and dont want to blow heat at all. Could it be my water pump? Then once the temp hand all of a sudden maxed out. So I pull over pop the hood and I could lay my hand anywhere under the hood and it was cool to the touch. Radiator cap was cool and hoses were barely even warm and with no pressure it seemed.

High temp on the hand but no heat and sudden spikes of running hot but nothing was hot at all. WTH?

tjwalker

The target coolant temp (via the gauge on your dash) is 200-210. Replacing the thermostat, while not going to help you with heat in your cab if the engine is running over those target temps, is never a bad idea as well is any basic cooling system maintenance. 195 degree stat only. I buy my stats from Jeep and also like the Stant SuperStat.

Also, be sure that you have fresh coolant at an approx. 50-50 mixture and that it is at the proper level in your coolant reservoir.

One of the usual suspects for marginal heat in the cab is a partially clogged heater core. You can sometimes restore function by backflushing (both ways) with garden hose pressure only; nothing stronger or your will damage the innards of the heater core.