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Heater questions

90xj06

NAXJA Forum User
Location
Peabody, MA
So I was trying to figure out if it's a me problem or a jeep problem. What's the temperature out of your center vent with heat on. I'm getting about 120 and it still seems cold. I'm going to try and check the heater core this weekend.
 
Check both heater hoses should be hot to the touch if not your heater core could be plugged up.
 
im going to try and clean out the heater core. blend door seems to work. should i be able to get about the same temp as the coolant out the vents? engine was showing about 195 at the time of the reading.
 
120* exactly in my center vent, and I just did a heater core swap. Full, complete flush of cooling system just before the swap, and blend door is opening properly on mine for sure. It just does not seem as hot as it should, I'm with you. My Ranger will literally cook you out of the truck!
 
i did a flush on the heater core itself. on my previose 90 xj i did a flush because there was no heat. and this disgusting rust colored paste came out in piles. and then i was roasting in the jeep.

on my 88 it was not nearly as clogged but what little much came out made a 40 ish degree change and its now feels like hot air. enough that you have to turn it down alittle.

just remove the 2 hoses going to the heater core and hold a hose to it not on a super high level. and let it flow the gunk out. then switch ports and do it the other way. i did mine a few times until the water was clean.
 
I have not found a solution to my issues. still 120* out of the center on fan setting 2.

I have a completely new cooling system and heater core over the last year, flushed each time a part was changed. Fluid is emerald green and clear. Only the water pump remains original. I have no overheating issues in the SC heat however; period.

I looked at the blend door, but it seems to rotate and seal perfectly each time.

All options considered, it looks like my water pump might be pushing fluid, but not enough volume/speed through the hoses? I'm kinda at a loss.... Just nice to have heat again though!
 
Yep. Running chain store 50/50 mix, and both hoses get nice and hot. No cabin filter that I saw when I took the dash apart either.

Sent from my LG G4 using TapaTalk
 
I'll give it another check when I swing by the house. I can get an IR and analog temp also from vents and engine, and watch the blend door again.

Is it possible that when I reassembled the AC/heater box, that the blend door should have been "indexed" with the motor, and it's not closing all the way on the heat side, but is on the AC side?
 
I'll give it another check when I swing by the house. I can get an IR and analog temp also from vents and engine, and watch the blend door again.

Is it possible that when I reassembled the AC/heater box, that the blend door should have been "indexed" with the motor, and it's not closing all the way on the heat side, but is on the AC side?

That's an interesting question. If you find out yes, I'd love to do that. I get cooked out of my jeep when it's 20* outside, blower on 1 and temp slider right in the middle.
 
Mine would go to where it was supposed to, but the issue is that they flex and don't stay put if that makes sense to you, its the best way I know to describe it. it would look like it worked, but was letting air move around it. or they will get stuck because the motor will try to move it to one side or the other, and itll push it too far in because it bends
 
I checked out the blend door last night, and watched it carefully. You could see the little shaft rotate back and forth, and it does look like it might be "overextending" as it hits the stops. I tested this by turning the temp knob not quite to the edge of rotation, and BAM! I've got 162* air from the vents.

I'll pull the motor off and look at it's indexing to see if it can be adjusted at all.
 
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