01 heater core/maybe something else?

Fox_91

Fox_91

Stihl Slinger
Joined
Feb 2, 2008
Messages
1,122
in my 01 the heat just plain doesnt get warm. the ac works great, but like said before the heat will barely get warm, sometimes struggling to defrost windshield, flushed cooling system and filled with correct amount of water/antifreeze, flushed heater core out, nothing un normal came out of the core. and when after truck gets to operating temp both the heater core hoses are warm, so....is this the signs of a bad heater core, or is it maybe a mode or blend door stuck and not putting the air into the heater core to get warm? also if it is the core, what is the best/fastest way to replace it? thanks.
 
I would check the blend door if coolant is flowing through the core it is good
 
I've got the same problem as you have. Maybe more will chime in with good info. Where's the blend door located?
 
I had the same issue awhile back, I changed the perfectly fine, functioning correctly thermostat and that resolved everything. I know it sounds stupid, but that was my issue. I felt a little foolish to have not tried that before I tore everything apart
 
The hoses through the core should be pretty darn hot, not kinda warm. You could still have some blockage in there from scale, I have heard of folks blowing them out with compressed air. What kind of flush did you use and what did the radiator look like so far as scale buildup? Also, what kind of airflow are you getting from the vents?

Blend door actuators have been known to fail, it's under the dash with the rest of the ducting, actuator is on the top IIRC. Might be able to access it with the radio out.
 
It's probably the core. I had the same problem on my 01. Flushed it, new stat and radiator. Still only had warm air at best. Replaced the heater core (it was all filled up with junk) and now it gets HOT.
 
I got the same issue with an 02. Won't get warm. However, I know that the coolant is full of oil now so at least the core isn't rusting out. LOL
 
hoses are hot, i will try the thermostat before i tear into replacing the core, and there was not much of anything to speak of scale wise out of the radiator
 
I flushed my heater core by taking off both lines, put a funnel with long neck in bottom hose, first blew out antifreeze with low air pressure, then poured in bleach, let set half hour, could not believe the stuff that came out after flushing with cold water, heat is 95% better
 
My heater core got partially clogged and all the flushing didnt help much so I just swapped the lines around by the head. Got full heat again and been this way for a yr now.

Edit: this is on my 01
 
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well im going to flush it again tomorrow and use CLR and let it sit for a half hour then flush it out again, if that doesnt help im going to swap lines at the head and try my luck with that, makes for a cold day when my own truck isnt warm then have to work outside in the cold!, ready to start working back in the shop..its atleast heated :doh:
 
smoken02 said:
Do you have to pull the dash to change the heater core?
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You dont have to remove it entirely. Just slide it back on the passenger side a ways.

White vinegar is the best route to try and remove core interior corrosion.
 
well CLR made no difference, so i swapped the lines at the head, got my heat back! just need to get a inch or two longer hose now because on the lines is a little tight.
 
Fox_91 said:
well CLR made no difference, so i swapped the lines at the head, got my heat back! just need to get a inch or two longer hose now because on the lines is a little tight.
Click to expand...

Now start flushing the system. Reversing the flow broke the debris loose.

tapatalking from droidx
 
CSnyder said:
You dont have to remove it entirely. Just slide it back on the passenger side a ways.
Click to expand...

Yep that's what I did. Used a ratchet strap to hold it :lolly:



You got lucky if you got heat after switching the lines. I think the other guy might be right, what ever was in there got knocked loose. Now you should flush it.
 
CSnyder said:
White vinegar is the best route to try and remove core interior corrosion.
Click to expand...

What's your method for white vinegar, I know Ive heard of this before. Pour it into the heater core or into the radiator and mix with water and run until it gets hot or what. And how much are you using. Thanks
 
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