i have a 2000 xj, and it has no heat. i have gone through most if not all of the steps i can think of to try and fix it. i replaced the water pump. i replaced the thermostat. i replaced the radiator cap. i replaced the blower motor resistor. i replaced the blend door motor, that did nothing. the blower motor works. the heater core is getting the coolant into it. i had the jeep at running temp and manually was moving the blend door to diferent spots and still no heat was being produced. if anyone has any ideas let me know
no heat in my xj
- Thread starter randy2kxj
- Start date
SteelHeadz
Super Moderator
If your planning on removing the t.stat again i would suggest that you disconnect the hoses to the waterpump, heater core, and if you have a plug on the side of the engine block for cooland drain, remove it. run a waterhose to the thermostat inlet(t.stat removed). see what comes out. if its rusty brown in color then you have an accumulation of casting media leftover when the engine block was casted.keep running the water till it starts coming out clear. do the same for the heater core.alternate the direction of flow from one side to the other.pay attention to the flow through the heater core. if you think it's not flowing properly then it's probably plugged with the same stuff thats sitting in your engine block.i hope this helps. as far as overcooling, there really is no such thing.my Cj7 use to have a heavy duty cooling setup. it's a solid mount between the waterpump pulley to the fan, always on. this setup just takes longer to get the engine on the normal operating temp.i've since replaced the radiator to aluminum and an electric fan with an adjustable fan t.stat. after replacing the engine from a 304 to a 360.
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i had a bit of time to think on the train today and i began to wonder if there was a chance that the heater core some how had a lot of crap built up on it. is there any way that junk can make it past the blower motor and get onto the heater core and cause the air going past it to not get hot? does this sound like a possibility
SteelHeadz
Super Moderator
Read the Prior Post. Yes it's most certainly possible that your heater core is plugged. However, it doesn't go through the blower motor, just the heater core. the blower motor just simply Draws the heat emmited from Heater core to the cab.
i meant that more as somehow alot of debris has gotten into the heater box and it caught on the heater core, in a way that would not allow the air that passes over it to become hot. kind of like the way a radiator can have to much crap on fromleaves and what not. i dont know im just kicking ideas around in my head because i want heat. i can wheel in the snow if i can see out the window
i meant that post in the way that there was a chance that somehow debris has gotten into the heater box and it has caused the air that is passing over the heater core to not get hot. im not sure if this is possible. i picture is like a radiator covered in leaves. it is not letting the air past it change temp. i am not sure if this is possible im just kicking ideas around. i really need heat soon so i can get ready to wheel in the snow and cold. cant wheel if i dont have a defroster that works
SteelHeadz
Super Moderator
Yes Sir that's a possibility.most common on jeeps with the top off most of the time in a very dusty environment or parked under a tree.
well every one i may have made a break thro. if you look at my above post youll see what i was thinking. well i took out the blower motor and i got to take a peak at the heater core. well it was covered in more crap that i can care to tell about. im about to take out the box and take that thing out and put in a new one. hopefully it will result in heat. ill keep yas posted.
fixed. it. well mostly. i took out the heater box and the evaporater was covered in more crap then i imagined. plus it had leaked out all its freon. so i put a new evaporater in and a new heater core and i have heat now. nice toasty heat. the onle problem is that the blower motor does not work on full blast. it works on 1 2 3 but not 4. ill look into that next time i got the time. the way i saw my evap was covered in crap was by taking out the blower motor. three bolts on the engine side. then i looked in and i was able to see a crap covered evap. well if this helps anyone awesome. if not well its something to try. at least looking at the evap could help. the heater core cost me around 67 and i got the evap for 137. Jjust Empty Every Pocket. all in all with calling for parts and labor and what not i finished in about 6 to 7 hours. a decent sunday i guess. but atleast i have heat
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