harorider848

heat works great when im driving, but when i come to a stop and jeep is idleing for about 5 minutes the heat starts to cool off and is just cool air blowing out. the only thing i can think of is something happening with the thermosthat. anyone have this problem

wilagobler

That would be my guess as well, thermostat failed open.

djb383

.....or clogged/restricted heater core.

1armyguy

I have this problem as well and have already replaced my thermostat and water pump due to a leak and the thermostat was weak anyway and wasn't sure as to what the previous owner had done pertaining to the maintenance. Better to be safe then sorry. I will try and flush out the heater core to see if that will help. I have seen threads that say back flushing the heater core has worked for others.

billfrank85

Make sure the vacuum line on the heater control valve didn't come off.

harorider848

thanks guy, yea i checked to see if i had a vacuum leak but it was connected. I will try to flush it out today.

djb383

Get one of these rubber thingys that attaches to your garden hose, works great to flush.

harorider848

where can you get that? lowes or any hardware store?

djb383

Not sure where anymore, had it for 30+ years now. Auto parts store maybe?