No heat, heater core or something else?

Ok I have a 97 XJ Country model with 238,000 miles on it now. I live in Georgia and for that past few weeks the weather has been nice so the heat hasn't been used. But the past couple days have been a bit of a cold snap and so I have attempted to use the heat and there isn't any. Air blows fine but it is as cold as it is outside.

Occasionally the air will get luke warm but hardly. The luke warm comes and goes too it isn't consistent. My Jeep's fan clutch is bad too so my Jeep runs a little hot about half way between the 210 notch and then next notch after so there should be plenty of heat.

I take fairly good care of my Jeep over then past 10 1/2 years. I have replaced the radiator twice, water pump 3 times (bought cheap duralast pumps), replaced the thermostat everytime major cooling system tear downs were done. Used quality prestone 50/50 mix antifreeze whenever coolant was added to the system. I did a heavy duty cleanse about a year and a half ago. Ran straight water and cleaning solution for 3 days, flushed, and re-filled with 50/50.

I know what needs to be done to clean a clogged heater core and how to check and see if that might be the case so I will be going through all of that here in the next week. I will check to see if the both heater hoses see to be the same temp. I will be getting a infrared thermometer to get a real reading and it is good to just have another tool!

Besides a clogged core, is there anything else it could be? I know older XJs had a vacuum actuated valve in the input heater hose that would open up the flow of coolant into the heater core when the heat was turned on inside. Does a 97 have something like this? Or maybe I have an issue with a blend door? Just need suggestions at what else to look at.

A 97 does not have a heater control valve.
Check your coolant level, find out why it's over heating...could be a clogged core. Could be more involved, but try the flush first.

ParadiseXJ said:

A 97 does not have a heater control valve.
Check your coolant level, find out why it's over heating...could be a clogged core. Could be more involved, but try the flush first.

Click to expand...

I am going to try and pull the cap and see if the radiator needs more fluid. The overflow bottle is almost empty so I will top off that as well.

New update on my situation, this morning on the way to work I was on the highway doing about 65 mph and had to punch it to get past a car so I could merge over for the upcoming off ramp. Shortly after getting over and coming back to 65 mph, the check gauges light came on and the temp was pegged out at 260. Luckily I was already getting off the off ramp at that point and coming to a stop shortly. Turned on the heat, still no heat, and after about 2 mins the temp started coming back down. It eventually settled back down at just above 210 during the rest of my drive to work. I am not sure what that means. The temp sensor is a cheap unit from Advance Auto Parts. I was considering getting a Mopar unit just to rule out a bad sensor.

ParadiseXJ said:

A 97 does not have a heater control valve.
Check your coolant level, find out why it's over heating...could be a clogged core. Could be more involved, but try the flush first.

Click to expand...

Agree.

If the coolant is properly filled, the next likely culprit on a WELL MAINTAINED system--like yours--would be a malfunctioning/broken blend door.

If filling the coolant doesn't cut it, try backflushing the heater core--easy on the pressure--and if that doesn't work you are likely down to the blend door.

DIY blend door fix: http://www.instructables.com/id/DIY-fix-for-Jeep-Cherokee-AC-Blend-Door-Failure/

Well to my complete surprise my coolant system was very low. I went and grabbed two jugs of 50/50 prestone on my lunch break to try topping off the system and filling the overflow reservoir back up. Well after letting it cool off I pulled the cap and poured in 1 1/2 jugs of coolant! I couldn't believe it was that low! I will admit with my job I have very little time to ever do hardly any work to my Jeep and I guess it had been longer than I thought since I had last topped off the system. I could tell the system needs a flush too as the fluid I could see in the neck was cloudy but I had to go ahead and pour the new coolant in to get me by. This next week I should have a free day to do a little work on the old Jeep. When I did fill the system back up I did make sure to burp it so I let it run for a couple of mins and topped it off some more. The engine had warmed back up some so I tired the heat and voila! Warm air again! So I think that was my culprit.

But while I have everyone's attention, when I have the setting to blow just on my feet, I still get alot of air coming from the side window defrost vents. Is that normal?

Ben824 said:

Well to my complete surprise my coolant system was very low. I went and grabbed two jugs of 50/50 prestone on my lunch break to try topping off the system and filling the overflow reservoir back up. Well after letting it cool off I pulled the cap and poured in 1 1/2 jugs of coolant! I couldn't believe it was that low! I will admit with my job I have very little time to ever do hardly any work to my Jeep and I guess it had been longer than I thought since I had last topped off the system.

Click to expand...

Job #1 is to find out why your are using coolant! 1.5 gallons of coolant is almost the entire capacity of your radiator!

You either are burning it or leaking it.

Perform a comprehensive search under the vehicle with a warm engine and a good light.

If you find no leaks, I'd start with a cooling system pressure test.

You gotta find the root cause here.

birchlakeXJ said:

Job #1 is to find out why your are using coolant! 1.5 gallons of coolant is almost the entire capacity of your radiator!

You either are burning it or leaking it.

Perform a comprehensive search under the vehicle with a warm engine and a good light.

If you find no leaks, I'd start with a cooling system pressure test.

You gotta find the root cause here.

Click to expand...

Pretty confident that it is the radiator. After my drive home from work, I was walking around the front of the Jeep to head inside and I could hear a hissing sound front the radiator. I am running an all aluminum Chapion 2 row radiator. They have had reviews of leaks forming but luckily for me they have a lifetime warranty so I will be trying to get it replaced. Good news though, my slight overheating issue is completely gone! Intact since filling the system back up the temp readings barely hit the notch before 210! Which is a little colder than I prefer. I am swapping to an electric fan and abandoning the mechanical fan so that should help. If it doesn't run hotter then I will swap in a higher temp thermostat than the 190 I have right now. I still plan to flush and cleanse the system but I think I have figured out my issue. Thanks for all the help guys!

The stock 192-195 is what you want. Not higher, not lower. If the radiator is leaking, you're losing pressure AND coolant. I'd address that first. Is your radiator the cheapo plastic tank version? If so, I'd be looking for an all metal 2-3 row (I prefer the 2 row, personally).

ParadiseXJ said:

The stock 192-195 is what you want. Not higher, not lower. If the radiator is leaking, you're losing pressure AND coolant. I'd address that first. Is your radiator the cheapo plastic tank version? If so, I'd be looking for an all metal 2-3 row (I prefer the 2 row, personally).

Click to expand...

My is a fully Aluminum tig-welded unit from Champion Radiators. They are some of the Cheapest on the market for this kind of radiator. They are hit or miss when it comes to these. Alot of guys have reported back that their radiators sprung a leak so I am not surprised here. Actually relieved that it wasn't something more severe.

So I called Ledfoot Racing who sells the Champion Radiators and is in control of Championradiators.com to figure out a warranty replacement since they have a "lifetime warranty" and they lady on the phone told me I have to pay to ship the radiator back to Champion for them to pressure test the radiator and depending on the problem they will repair the unit or send me a new one. So I have to be without the only car I own for an undetermined amount of time while also paying to ship it back and forth. To say I was upset is a drastic understatement.

So I tried to see if I could call Champion directly and sure enough I could! So I talked to Veronica over there and she said I can pay $145 (Cheaper than the $169.98 through Champion) and they will send me another one that I can swap out immediately and then ship the old one back. If they determine that is was indeed a manufacturer defect then they will refund my $145. This is what I was expecting to hear when I first called Ledfoot. So if you want one of these radiators, which I highly recommend since they are amazing at cooling, then call Champion directly. Their website is Championcooling.com, not Championradiators.com or Championradiators.net.

A little update, talked with Champion directly today to settle up me getting another radiator and she said "I have one small problem, I don't have anymore 2 rows and all I have now are 3 rows. Is it ok if I send you a 3 row at the same price?" Sure why not haha so I am getting a 3 row radiator now!