No heat

[HeavyMetal]

The heat in my 2000 XJ doesnt work. Thats all I got for ya.

Any suggestions where to start? flush heater core?

[Ruepart Hoaxley]

Pull the panel and check that all the vacuum connections are good to start.

[customcreationsllc]

are the heater hoses hot? that will tell you right away if you have flow through the heater core. Remember if you have been running a while everything will be hot. so check it a couple minute after running.

That should be the first thing. if there not hot or only 1 a little bit the core is clogged try swapping hoses 1 is a little larger but you can sometimes stretch it.
Don't break it just buy a coupler and do it in the middle of the hoses.
We use like a air powered pressure washer to flush them but just reversing the flow usually does the trick.
Pretty sure that year doesn't have a heater control valve, which stops the flow to the heater core when you don't command heat, usually on the older XJs.

If the hoses are hot then your core is fine and you have a control issue check the doors are opening link didn't fall off etc. I work on to many cars to remember if it is vacuum or stepper motor but I'm sure you can figure it out. A short term fix just prop the door.

[92xjlaredo]

not too long ago my friends 01 XJ had no heat. as he describes it "just enough to tease me" turns out it was a bad actuator for the flappy paddle thing to change from hot to cold. wasnt sealing up enough to give him heat. i would say check the 4 port vacuum valve but if im not mistaken that was done away with in 97 in favor of the electronic actuator setup. perhaps?

[Burton58]

Keep an eye on the temp gauge just in case. Prob not the case but if its overheating you can lose the heat

[wannabejeep]

not too long ago my friends 01 XJ had no heat. as he describes it "just enough to tease me" turns out it was a bad actuator for the flappy paddle thing to change from hot to cold. wasnt sealing up enough to give him heat. i would say check the 4 port vacuum valve but if im not mistaken that was done away with in 97 in favor of the electronic actuator setup. perhaps?

flappy paddle = blend doors.

My heat used to only work out of the defroster, but tonight I can get it to come out of all the settings.

[92xjlaredo]

yeah i have not a single clue really. i know dads 98 hasnt ever had problems with them and ive never had a late model XJ so i really dont know shit when it comes to that...just more or less putting what little insignificant chunks of info i have on the table.

[crosbike]

flappy paddle = blend doors.

My heat used to only work out of the defroster, but tonight I can get it to come out of all the settings.

vacuum issue

[Kyle]

Blower motor resistor?

[StompJrKz400]

not too long ago my friends 01 XJ had no heat. as he describes it "just enough to tease me" turns out it was a bad actuator for the flappy paddle thing to change from hot to cold. wasnt sealing up enough to give him heat. i would say check the 4 port vacuum valve but if im not mistaken that was done away with in 97 in favor of the electronic actuator setup. perhaps?

flappy paddle thing



or did you mean the air blend door actuator ?

[Zullock Holmes]

heat is for nancy's.

[HeavyMetal]

so i flushed the heater core a couple times the best I knew how...cleared out some gunk definitely, even took the hoses off and cleaned them out separately.

right now it blows ambient temp/warmish maybe air at idle, if i get on the gas and rev it, i get maybe 50-75% power heat out of it. i checked the inlet and outlet lines to the core and one is hot the other is only warmish...from what i understand this is a tell tale sign of a clogged core.

not sure WTF else I can do to this thing...i had both hoses off flushing the core directly with a garden hose and it seemed to flow water through it ok.

bueller?

[Hudson]

so i flushed the heater core a couple times the best I knew how...cleared out some gunk definitely, even took the hoses off and cleaned them out separately.

right now it blows ambient temp/warmish maybe air at idle, if i get on the gas and rev it, i get maybe 50-75% power heat out of it. i checked the inlet and outlet lines to the core and one is hot the other is only warmish...from what i understand this is a tell tale sign of a clogged core.

not sure WTF else I can do to this thing...i had both hoses off flushing the core directly with a garden hose and it seemed to flow water through it ok.

bueller?

Not sure how much it helps, but i was taught to reverse flush those. Run water through it one way, then run water back through where the water was previously coming out of.

Not sure if it'd be worth it to undo everything again just to do that though.

Have you confirmed that the heating system has no leaks in it?

[HeavyMetal]

Not sure how much it helps, but i was taught to reverse flush those. Run water through it one way, then run water back through where the water was previously coming out of.

Not sure if it'd be worth it to undo everything again just to do that though.

Have you confirmed that the heating system has no leaks in it?

i flushed it both ways repeatedly, should have mentioned that.

i have not confirmed the leak aspect, not sure where to start with that.

FWIW before i did any of this, the jeep wouldnt blow any sort of warm air under any circumstance.

[Kyle]

Time for a new core.