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98 Cherokee Sport NO HEAT!!! #1753075 02/12/15 03:40 PM 02/12/15 03:40 PM
Joined: Oct 2003 Posts: 1,244 Eastern,NC 6 68GTS383 OP pro stock
68GTS383 OP pro stock 6 Joined: Oct 2003 Posts: 1,244 Eastern,NC	I have a 98 Cherokee with 4.0 and I can not get the heat working.It only has 118K miles and runs like a top. A/C works but the Heat does not.I have changed thermostats a couple of times but it does not help.Any ideas on my problem? Thanks!

Re: 98 Cherokee Sport NO HEAT!!! [Re: 68GTS383] #1753076 02/12/15 04:24 PM 02/12/15 04:24 PM
Joined: Jan 2003 Posts: 21,065 Niles , Ohio T therocks oh wait.but hey.lets see.oh yeah.
therocks oh wait.but hey.lets see.oh yeah. T Joined: Jan 2003 Posts: 21,065 Niles , Ohio	Check the heater hose.Both should be hot.I take it it blows cold air?If they arent both hot either the valve is bad or the core is blocked.Possibly a problem with blend doors but we never saw many problems with them at the shop.Rocky Chrysler Firepower

Re: 98 Cherokee Sport NO HEAT!!! [Re: therocks] #1753077 02/12/15 05:19 PM 02/12/15 05:19 PM
Joined: Sep 2007 Posts: 1,890 Spahn Ranch RMCHRGR top fuel
RMCHRGR top fuel Joined: Sep 2007 Posts: 1,890 Spahn Ranch	Quote: Check the heater hose.Both should be hot.I take it it blows cold air?If they arent both hot either the valve is bad or the core is blocked.Possibly a problem with blend doors but we never saw many problems with them at the shop.Rocky X2. You'd likely know it if it was a blend door, you'd probably hear it clicking or something when you switched modes. Sometimes you can stick your head under the dash and look behind the console at the box (with a light of course) and kinda see if it's working. Probably a heater core. They go bad, especially on an 18 y.o. car. Zillions of GCs from that time have had their heater cores replaced. '71 Duster '17 Ram 1500

Re: 98 Cherokee Sport NO HEAT!!! [Re: RMCHRGR] #1753078 02/12/15 06:35 PM 02/12/15 06:35 PM
Joined: Jan 2003 Posts: 32,923 Grand Prairie,Texas stumpy I Win
stumpy I Win Joined: Jan 2003 Posts: 32,923 Grand Prairie,Texas	Use a garden hose to clear the heater core. Run the water in both directions in the heater hoses to and from the core until you have free flow through the core.

Re: 98 Cherokee Sport NO HEAT!!! [Re: stumpy] #1753079 02/13/15 12:12 PM 02/13/15 12:12 PM
Joined: Aug 2004 Posts: 8,087 Elk Grove, Calif. B bigblock340power master
bigblock340power master B Joined: Aug 2004 Posts: 8,087 Elk Grove, Calif.	Just went through this a few months back with my '98 GC. One of two things. Heater core blocked, blend door not working properly. Mine turned out to be the heater core. I checked the two heater core hoses coming out of the fire wall. Both were hot. The core was not blocked all the way. But enough to make the heat turn cold when fan was going faster than on "low". Does the heat seam to work a little when you first turn the heat on (when everything is warmed up), then quickly turn to blowing cold when you run the fan on mid, or high? I did the flush/back flush thing, and it seamed to help at first (a little). But not for the long term. When you do the flush/back flush of the H core, flush the whole system too. Their is a lot of info on you tube about this. Some vids on how to fix. Good luck. Oh, by the way. I ended up having to change the heater core.

Re: 98 Cherokee Sport NO HEAT!!! [Re: bigblock340power] #1753080 02/13/15 01:29 PM 02/13/15 01:29 PM
Joined: May 2004 Posts: 4,920 Joplin, MO USA Robbins master
Robbins master Joined: May 2004 Posts: 4,920 Joplin, MO USA	Yep....try cleaning the heater core out....the way they suggested works great. Moparlee

Re: 98 Cherokee Sport NO HEAT!!! [Re: Robbins] #1753081 02/13/15 08:11 PM 02/13/15 08:11 PM
Joined: Oct 2003 Posts: 1,244 Eastern,NC 6 68GTS383 OP pro stock
68GTS383 OP pro stock 6 Joined: Oct 2003 Posts: 1,244 Eastern,NC	How hard is it to change the heater core?

Re: 98 Cherokee Sport NO HEAT!!! [Re: 68GTS383] #1753082 02/13/15 09:05 PM 02/13/15 09:05 PM
Joined: Jan 2003 Posts: 32,923 Grand Prairie,Texas stumpy I Win
stumpy I Win Joined: Jan 2003 Posts: 32,923 Grand Prairie,Texas	It's a lot easier and cheaper to flush than change and normally flushing will work.

Re: 98 Cherokee Sport NO HEAT!!! [Re: 68GTS383] #1753083 02/14/15 03:20 AM 02/14/15 03:20 AM
Joined: Sep 2007 Posts: 1,890 Spahn Ranch RMCHRGR top fuel
RMCHRGR top fuel Joined: Sep 2007 Posts: 1,890 Spahn Ranch	Quote: How hard is it to change the heater core? It's not 'hard' per se but it's a big job. The dash has to come out, (which entails a lot of little stuff) or at least pull it back enough so you can get the housing out. You can usually pull it back to where you can rest it on the front seat and get to the housing. Need an A/C machine, coolant has to be drained. Inside there is lots of plastic to deal with, wiring to disconnect, console, shifter, steering column needs to drop or come out. If you've done 'em, you have your methods and can probably get it done in around 3-4 hours if you hustle. Cordless driver will be your friend. Usually pays like 6-7 hours, maybe more. Last one I remember doing was on a 300, I was the first one in our shop to do one on that car. We actually had two come in at the same time. Took me all day but I somehow beat the guy who could do a Grand Cherokee heater core in under 3, he'd never done one either. So yeah, big job but Cherokees are probably easier than other cars. Simpler and more room. Forcing water through the core won't do much. They clog up and corrode and the fins get blocked up. Usually find leaves and stuff in there. '71 Duster '17 Ram 1500

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