2001 cherokee- water temp gage indicates 210 deg. When temperature **** set to highest heat setting only get luke warn air from vents. Just bougth jeep so don't know what previous owner did or did not do. But here in MN with temp -12 need all the heat I can get. Of course defroster effected as doesn't clear windows.

 

When engine is at operating temp, are both heater hoses getting hot with heat mode on the control panel set to full hot?

 

Also, depending on how many miles you jeep has and it's previous life, you may have a cracked head which is creating a milky gummy substance from oil and coolant mixing, which could be clogging up your heater core. Ask me how I know! Could be other things, but that was my experience.

 

Yeah, it appears to be a 2001, which does have the infamous and dreaded 0331 head. But let's not go there quite yet.

 

Don't jump to conclusions and the possible major problems just yet.

As Firestorm said in his earlier post check the heater hose to see if they are both the temp. With a little luck all you may have to do is give the heater core a good flushing in both directions several time. Hopefully that will take care of the lack of heat.

 

Just to add, also make sure the heater control valve is working properly. It can be visually inspected through the passenger foot well area behind/near the center console.
A cracked (or uncracked) head should have no bearing on your condition if 1) your engine does get up to the operating temperature, e.g., gauge reads ~210, etc., 2) your coolant reservoir is at the correct level, and 3) the coolant quality has not been compromised due to age.

 

No heater control valve on a 01. Heat is controlled by the blend door which I think you are talking about since that is located under the dash as you are saying.

 

I stand corrected. That's exactly what I meant to say. Thanks for the correction.

 

Isnt that one vacuum actuated? Or was that in older XJ's?

I'd check if heater hoses are getting hot
check coolant quality
flush the heater core (good maintenance and probably never done since only 2001)
let us know how this goes

 

Blend-Air Doors aren't vacuum actuated. 99-01 are operated by a servo motor and prior years are push/pull cable operated.

 

Cable actually, electric servo in 1999+

I agree check the heater hoses. Clogged core is most likely.

 

Thanks for clarifying.

Aah, could I be mixing that up with the vents, that are vacuum actuated?

 

Yeeees

 

Ah ha. Weather finally went from -18 to 32 yesterday and heat improved considerably that I had to turn down indicator **** on "red" display. I'm believing problem is as was mentioned heater core needs good back flushing. As I can not do this in sub 0 weather, mechanic I have used for big jobs on other vehicles, said he can back flush and clean for $50. I think this will be money well spent.

Oh turning temperature indictor **** from high blue to high red give significant change in temperature at vents, so I am ruling out blend door issue, unless someone can give me reason to still consider.

 

I'd say your blend door appears fine.
$50 for that service...30 min of labour alone will cost you that these days...
Although its really not a pain to do, and could easily do this yourself...for $50 I'd might just treat myself and have that mech doing it in the cold...