8robinson8

So i have solid heat at temps 40 and higher...But when it gets colder 40 and below my heat just doesn't work.. I tried flushing the whole system, heater core. Burping whatever... Even checked the heater core for leaks, etc. Heater inlet and outlet hoses were scorching hott... After all that still none of it worked. So i went to the blend door... Well i cut into it behind the glove box and found my blend door works flawlessly. So what else could it be? I started to play around a bit and got to thinking well if i am having heat when its sorta warm out but not freezing and when its freezing and below i have no heat well that's when i went straight to where the air gets sucks in from the out side. Which is directly below your right windshield wiper. So i said to myself maybe the cold air its sucking in is too cold for the heater core to warm up efficiently...So i figured ill cut a whole right in front of the ac/heat intake and let my engine bring in some warm air since it runs at about 200-210. I defiantly put a filter on it because i wasnt about to have any headaches or pass out due to fumes.. Kinda of stupid of me to do so but you know sometimes you have to role the dice!!!!

Well Ive been running it like this for about a week now and have no headaches cant smell anything different and the best part is the heat is much warmer and stays hot through any temperature. I hope this may help someone... Btw way i have a 1998 Jeep Cherokee Classic it has the cable for the blend door also...

JerrytheJeep

Sure it'll keep you hot, but what if you want cold?

8robinson8

Well its high in the 40s today and i tried it out already and it gets really cold... But i wont be able to tell you a straight answer until the heat comes... I can always go back to the way it used to be if i don't get any cold air. But right now I'm worried about heat... Besides i am more of a windows down type of dude... This is my DD so heat is a necessity..

alpine.adrenaline

Hold up, when you say it "works flawlessly" do you mean you were able to wiggle it back and forth with ease, or did you cycle the climate control **** and watch it operate?

8robinson8

I didnt even put my hands on the blend door i literally cycled the climate control and watch the blend door move back and forth just like a door... There was NO wiggling

alpine.adrenaline

Does your heater core feel hot?

PocketsEmpty

Interesting solution, but I'd be more interested in knowing the actual cause of the problem. My heat is room temperature at best. But I've been redoing the coolant system since I got my XJ due to the ignorant PO putting stop-leak in. Haven't had a chance to back-flush the core quite yet...but knowing my luck, it won't solve my problem either.

JerrytheJeep

Its probably your heater core...

8robinson8

Yeah my heater core gets hot... And yeah it sounds like your heater core is clogged they you can use CLR but you need to be careful to thoroughly rinse your system out... I would def try everything before you resort to what i done... The temp here is in the teens and i have a pretty good flow of heat now...Still no fumes no headaches nothing...

PocketsEmpty

I flushed my core over the weekend and this was the result:



Raw sewage. This is even diluted some after it came out clear. I now have heat!!

andyval

i had the same no heat issue. 98 sport i6 4.0. i flushed the heater core using clr (8 oz in a gallon of water) let the mix sit for 5-10 mmins. use compressed air to push the mix out. be careful and hold or tie down the hose becaue they spray every where ( found that out the hard way lol). jsut like the pic from pocketsempty is what came out of my heater core. i also thuroghly flushed with just water then a i continued to burp the air from the coolant system and now i have great super hot heat lol.

PocketsEmpty

Did your PO also use stop-leak in the cooling system? SMH! I've had to replace freeze plugs and the radiator so far because of the damage done by that junk. I do feel like my heat could be better even after the flush, but it's definitely satisfactory. I'm sure using CLR might provide even better results...might try that out

andyval

forgot you mentioned stop leak. yeah that crap causes more harm than good. if you do go with the clr just dont let it sit soak for too long. GOODLUCK with bringing the coolant system back to life. YOU GOT THIS!

8robinson8

yeah i had done everything you guys have...Just never got any hot heat... Except unless it was over 40 degrees... But idk my solution helped tremendously...