Jeep Wrangler Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JUNE's Ride of the Month Challenge!

1 - 16 of 16 Posts

·
Registered
Joined
·
37 Posts
Discussion Starter · #1 ·
Hey Folks,

Been looking around on here trying to find a solution to not having any heat in my newly acquired 98 Wrangler.

Followed the usual suspects: Clogged heater core, thermostat, water pump and even though nothing became obvious flushing (No Gunk) and/or changing things out (new stat and water pump) I now have more heat than before but have a question about my fan clutch.

If I've read on here correctly when the engine is cold the fan should spin relatively freely by hand. Once the engine is running the fan will spin but probably not top speed and once the engine is at operating temp it will spin faster in order to cool the radiator. I can turn the fan by hand when the engine is cold but it doesn't spin freely at all...there's resistance.

So my question is, can having a fan clutch that is always engaged keep my heater core from putting out max heat? If it is stuck engaged should I change it out...what does it hurt other than sounding like a jet plane?

Dash gauge stays right under 210° once she warms up and the dash vent is about 130° (using a kitchen probe thermometer in the vent). Outside temp was 65° when I was able to work on it so I don't know what temp to expect from the duct.

Thanks for any insight or education anybody is willing to throw out there.
 

·
Registered
Joined
·
538 Posts
The fan clutch should spin some, but not completely freely. 210° seems reasonable.

Internal heat is controlled by the blend door which splits the air in the HVAC box so some, all, or none flows through the heater core. The blend door on the 98 is cable driven by the slider. It connects below the passenger feet. Check and see if it is moving that small arm fully. There may even be debris in the HVAC box limiting the blend door movement.
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #3 ·
Thanks.

The cable seems to be allowing the door to move all the way when selecting heat but I guess that doesn't necessarily mean there isn't debris in the HVAC box.

Don't suppose there's an easy way to tell if the door is moving to the right spot as opposed to stopping against something in its path is there?
 

·
Registered
Joined
·
538 Posts
Thanks.

The cable seems to be allowing the door to move all the way when selecting heat but I guess that doesn't necessarily mean there isn't debris in the HVAC box.

Don't suppose there's an easy way to tell if the door is moving to the right spot as opposed to stopping against something in its path is there?
xray vision? Really, I don't see how... But maybe you could pull the blower motor (under the hood) and run a vacuum in there / and a fiber cam?
 

·
Registered
Joined
·
57 Posts
I also have a '98 TJ that had no heat. I ended up having to replace the heater core once I exhausted multiple other options. My heater core was leaking coolant onto the floorboard, which was the dead giveaway for me. And once it took it out it was very apparent it needed changed. So my question would be do you have a coolant smell or puddles on your floorboard or spatter on you windshield when you turn the heat on?
 

Attachments

·
Registered
Joined
·
37 Posts
Discussion Starter · #6 ·
Hadn't thought about an inspection camera. Great idea!

No coolant smell or any other indication that she's leaking so either she's still a little gunked up and I haven't managed to break it loose yet or the blend door is giving me grief somehow.

Anybody have an opinion on the fan clutch?? Could the fact that it seems to always being engaged keep things too cool? (if there is such a thing) Will it hurt anything if it's always at max or should I just change it out since they're relatively cheap and it doesn't look to be too tough a job?
 

·
Registered
Joined
·
538 Posts
You said the temp gauge is reading "right under 210° ", so the fan clutch is probably working properly.

I replaced my heater core in my garage. It was at least a 4 hour job for me. YMMV. There are a couple of "write ups" you may be able to find online. There are a few foam seals you should buy in addition to the heater core if you're going to pull the HVAC box.
 

·
Registered
Joined
·
945 Posts
You said the temp gauge is reading "right under 210° ", so the fan clutch is probably working properly.

I replaced my heater core in my garage. It was at least a 4 hour job for me. YMMV. There are a couple of "write ups" you may be able to find online. There are a few foam seals you should buy in addition to the heater core if you're going to pull the HVAC box.
4 hrs complete?! No way. You tore out dash etc?
 

·
Registered
Joined
·
538 Posts
4 hrs complete?! No way. You tore out dash etc?
At least 4.. Maybe 5. Yes, the dash skin came out. If you have a convenient work place, all the tools, and some experience, it can be done.

Napa repair estimates range from $380 to $480. Shops typically get $80 to $100 per hour, so 5 hours sounds about right.
 

·
Registered
Joined
·
945 Posts
At least 4.. Maybe 5. Yes, the dash skin came out. If you have a convenient work place, all the tools, and some experience, it can be done.

Napa repair estimates range from $380 to $480. Shops typically get $80 to $100 per hour, so 5 hours sounds about right.
For a TJ heater core? No way on gods green earth! In NE a dealer n jeep shops want a solid $900!
 

·
Registered
Joined
·
741 Posts
Dash gauge stays right under 210° once she warms up and the dash vent is about 130° (using a kitchen probe thermometer in the vent). Outside temp was 65° when I was able to work on it so I don't know what temp to expect from the duct.
130 deg out the vents is quite warm. Not sure why you would want it any hotter.
 

·
Registered
Joined
·
538 Posts
For a TJ heater core? No way on gods green earth! In NE a dealer n jeep shops want a solid $900!
That includes parts. The price I posted was just the labor. There is another $300 in parts, so that would be close to your $900.

http://www.jeepforum.com/forum/f9/heater-core-replacement-without-dash-remaoval-520805/

Post #2
"This was my second time taking the heater core out and I think it took us just under three hours, much faster than the first time. " Removal only maybe? Not clear

Post #4
"The easiest way is to remove the dash and pull out the evaporator case... I did it twice in about 2 hours the second time around... "

I don't think they saved much time by not removing the dash completely, but it may have helped. They still had to unbolt it and lift it upwards.
 

·
Registered
Joined
·
57 Posts
When I did it it took me 8 hours but that was a late start the first day and two trips to Sears for tools I needed
 

·
Registered
Joined
·
57 Posts
When I did it it took me 8 hours but that was a late start the first day and two trips to Sears for tools I needed
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #16 ·
130 deg out the vents is quite warm. Not sure why you would want it any hotter.
That's kinda why I'm asking if I've gotten all I'm going to get and it's working like it should or if there's more to hope for. I've had some folks tell me their heat is like a pipeline to hell and my need for things to work (even if I might not necessarily need them) is forcing me to make sure this is right before moving on to the next item on the list.

Yeah...it's a little bit of a mental disorder that I just try to work through...
 
1 - 16 of 16 Posts
Top