droff85

it was very cold outside today playing in the mud and snow while we had it. we ended up getting about 2 inches here in north mississippi. i was hoping someone might have some advice on how to fix my heat. I replaced the heater core, radiator, and expansion tank right after I got it (the previous owner had just water in it and everything froze, thankfully the block just pushed a freeze plug out rather than cracking it) well any way the fan blows hard out of the vents but it isnt hot air. I checked the blend door and it is openning fully with the dash controls. I am new to cherokees so I dont know where else to look. any help is very appreciated. by the way it is an '88, 4.0L, auto.

shr1125

I had this problem up until about a week ago and in South Dakota, it's a real issue! The thermostat may be broken and stuck in the open position. If this is the case, the broken thermostat would never allow the engine to warm up, and thus, never blow hot air.

Steve

nick_n_ii

My brothers XJ and my ZJ both have it, the thermostate on his XJ wouldn't open all teh way. And mine if after 20 min I'm not blowing heat I stop shut off the engine than restrat with heat..

droff85

thanks but I forgot to mention that I put a new thermostat in when I did eveything else b\c someone had stolen the one in it. but I figured out what the problem was after my heater control valve inline to the heater core busted on me at operating temp. luckily I only got burned where my watch was. the thing had apparently stuck closed. had a manual valve laying around from an old project that never got used and put it in. now the heat will burn you out when it is 20 outside.