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heater only blows warm air when heater is on

18K views 10 replies 7 participants last post by  vondy7 
#1 ·
Here's a heater questions for you experts...

It's starting to get cool outside so I turned the heat on in my 2000 Grand Cherokee for the first time this season and all I get is warm air, not hot. My temperature gauge on the cluster panel reads 190 degrees like it should. I don't believe there is an issue with the thermostat because it is not running cooler or overheating. I flushed out the heater core this morning to be sure that it was not clogged and it seemed to be clean and flowed freely. I do hear a water "sloshing" sound behind the dash. I don't know if this is a related issue or not. I have no antifreeze smells or leaks inside the vehicle. A/c runs fine.

Any suggestions are appreciated.

thx
 
#4 ·
Possibly there is a problem with the heater door under the dashboard.
If that does not open completely you are having the problems you are describing
Your local dealer should be able to make a quick test to find that out
That does not last more than 10 minutes
 
#5 · (Edited)
If you have the AZC system, you could do a calibration on the system, to be sure that all doors move freely and full travel. You could also check for eventual fault codes stored. see here: Jeep Grand Cherokee WK - Climate controls
PS: eventhough the sites name shows WK, its the WJ section.
 
#8 ·
i have a rather strange issue, i cold air and warm air but no hot air... garage and google search have said its blend doors, i replaced these today did the battery disconnect etc and still no change.. the heater pipes in the engine have been checked and are hot (checked by a mechanic).. i have only just bought it and its clearly had a new radiator and water pump thats about all i know.
Jeep Grand cherokee 01 limited
 
#9 ·
I finally changed out the heater core after having back flushed the system, checked blend doors, and replaced the thermostat and the problem has been resolved and my heart it's actually hot again. It is a labor intensive job to replace the core which makes it a little pricey. Appears there was probably a partial clog in the core and was not letting the hot coolant throughout the entire core to warm it up. According to the mechanic there are different chambers and routes that the fluid can travel and therefore just because your tubes that go to and from the core are hot, doesn't mean the entire core is getting the same heat. Hope this helps anyone else.
 
#10 ·
Sounds like my same problem. The heater core is my last thing I'm going to change hopefully. What brand did you end up going with. I need to check those doors too. ANyone want to do a good write up on the procedure? I have looked at wjjeeps as well. I remember having the same problem with my old 1990 Cherokee.
 
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