I have a 2000 xj with 132xxx miles and I'm having some issues with my heat. At first i had close to no heat so I changed my thermostat and replaced all of my hoses and flushed the system. That still didn't work so I went to the car wash disconnected the hoses after the heater core put the power washer in there and flushed it out. Alot of rust water came out and my heat got better! When at idol at opp temp my heat is warm but when I start to drive or give it gas it gets hot. Is the heater core possible still clogged ?

 

Anyone plzzz help??

 

could the heater core being clogged OR the sensor. I'm dealing with this as well. That is what the local mechanic told me. I've replaced everything but the heater core sensor and the heater core it's self. Not sure if I'm any help to you.

 

If a lot of rust came off the core then you most likely have a bad core. The veins or passages could be either clogged up or busted up...so, the hot water is not being efficiently pulled by the fan...makes sense? I would change it out...

 

a job that i didnt want to do lol. theres a heater core sensor?

 

It sounds like my issue. No heat... flushed the entire cooling system and came out rusty brown. My main issue was wth my heater control valve all clogged up as well. All I was gettin was a slight trickle then all of the sudden it all blasted out. (The heater control valve should be right before your heater core up against the pass side of the firewall.) Now it gets sort of warm. Pretty sure theres still tons of sht cloggin it up but its good enough for now. lol..

 

On 2000' s there isnt a heater conrol valve. Go to the car wash and disconnect your hoses going to your heater core and shove the water sprayer in there and give it hell, thats what i did and i went from cold air to almost what you would call heat lol

 

2000 doesnt have one? I thought up until 2000 had one. huh... my 90's sure got one... regardless... flush it a few times... im gonna do mine again, the heat is still leaving me wearing gloves on brisk morning drives to work...

 

this happened to my 99 xj did everthing including core problem ended up being teeth on water pump were sheared off. showed to mechanic he said he never saw it happen before good luck

 

Ithink they eliminated the heater control valve in 97. I have an 88 and took the stupid thing off. Does nothing but leak from the day they are new. My heat works awesome.