93Cherokee2wd

i have a 93 Cherokee 4.0 5 speed 2wd this thing has no heat have a 192 stat but no heat out of the heater hoses are hot but nothing inside any idea's short of changing the core ?

F1Addict

First, check to make sure the heater valve is opening when you turn the heater on. The valve is located on the hard line in the engine bay near the firewall on the left side of the engine. If it isn't working, either replace the valve or remove it and connect the two ends of hose that once went to the valve. If it is working properly, your heater core is likely clogged with sediment and needs to be replaced. A last ditch effort would be to disconnect the heater hoses and try backflushing your heater core but be prepared, this occasionally cause leaks where there previously weren't any.

[Edit] I'm not sure if the heater valve is vacuum operated on a '93. If it is, check the vacuum line that makes it work for leaks. If you find them, patch or replace the vacuum line and retest.

Jeepwalker

The possible causes are:
1) Low coolant

2) Stuck thermostat (not opening). When warmed up and running, feel the hoses that go to/from the heater core how hot they are. They should be SO hot you can barely hold onto them.

3) Valve not opening (that was covered). You can manually move the stem when the vehicle is running and feel if the hoses become hot.

4) Inside vent flap not operating. On my heater core, somehow the vacuum actuator came off the door lever. Hoses can get kicked off too. So, look under the dash and the kick panel to make sure all the actuators' connectors (cables and vacuum hoses) are connected ....and working.

5) Plugged heater core. If all the above don't yield results, remove the hose ends which go into/out of the heater core. Use care. Get an angled and pointed tool under the hoses and loosen the hoses from the metal heater core end. Don't start tugging on the hoses or get rough with them. A tool like a cotter pin puller works well. Remove the heater hoses and put a garden hose (that's turned '0n') to the "outlet" (not the inlet) ....but the outlet. The idea is to reverse-blow water into the core and blow out any debris that may have built up inside. Sometimes a surprisingly large amount of crud comes out and the results can be astonishing. Don't listen to these guys here who keep telling to remove the heater core valve. I've had just as much crap build up in other jeeps that DON"t have valves.

93Cherokee2wd

valve seems to be working full of coolant temp gauge barely comes off cold but during the summer it ran almost middle way have not checked the stat yet

Turbo X_J

I don't think you have to, just replace it.