Cold air is blowing hot

[tennant]

I took my TJ out for a drive today and I noticed the cold air (not AC) was hot as hell. and then i noticed the underneath part of the dash was hot near my feet.

I also noticed when driving, The temp gauge was SLIGHTLY more to the right of “neutral” towards hot.

Radiator was just replaced. Has about 91k miles on it. it’s a 2005.

Anything?

 

[Chris]

It's possible your blend door is stuck. When you turn the temperature dial, do you hear any noises behind the dash like the blend door opening and closing?

 

[tennant]

It's possible your blend door is stuck. When you turn the temperature dial, do you hear any noises behind the dash like the blend door opening and closing?

Not that I could hear. It was just hot and underneath is hot too. The area/hole where the parking brake is, seemed to be warm inside if I put my hand over the brussle.

 

[Chris]

It seems to me that your blend door could be stuck.

For the temperature gauge to be slightly above the middle mark is 100% normal.

 

[Sundy]

What Chris said.

Also I know the XJ 4.0 is notorious for catching air in the cooling system. I think a fix is to park with the front higher than the rear and add coolant as air burps out of the radiator cap.

 

[tennant]

It seems to me that your blend door could be stuck.

For the temperature gauge to be slightly above the middle mark is 100% normal.

I think when I wrote this thread, I thought it was the temperature gauge but it was actually the oil. (top right)

 

[tennant]

What Chris said.

Also I know the XJ 4.0 is notorious for catching air in the cooling system. I think a fix is to park with the front higher than the rear and add coolant as air burps out of the radiator cap.

I’m not mechanically savvy 100%. Should I bring it to someone?

Just the heat coming from underneath basically anywhere near the dash/parking brake/clutch/stick etc seems to be warm air when your hand hovers. Faster i drove the hotter it seems to get or at least more noticeable.

 

[Steel City 06]

I agree it's likely the blend door.

The heat gets hotter in any vehicle when you step on the gas, because the coolant flowing through the core is hotter, and because the flow increases as the water pump speeds up as the engine RPMs rise. The effect you are feeling there is 100% normal, if the heater is on.

If it is the blend door actuator, I believe the dash has to be removed to fix it. (I could be wrong.) Expect the labor for the job to be hella expensive. Like 1k expensive. Dadh removal is an all day procedure. (Parts are much cheaper.)

If I were you I would bribe a buddy who has removed a dash before or is mechanically inclined with lots of beer and pizza and spend a day pulling the dash. There's got to be some good YouTube videos on how to do it. Far easier with 2 people

 

[Goatman]

Heat in the trans tunnel is totally normal too. You have air from around the engine moving back as you drive. It can be even warmer if you are not moving.

 

[Bird-Dawg]

I just spent to many hours in my 1999 TJs HVAC box installing AC so the layout is pretty fresh in my mind, i'm not sure if it is different for 2005 so this may all be wrong. For the 99 you do not need to yank the dash to replace the blend door. It will still be a PITA but doable. On the passenger side, under the dash above the floor board there is a curved plastic shield that protects the HVAC box that is held on by 4 screws. Once this shield is off you will see all the vacuum actuators and the blend door motor. The blend door motor is held on by 3 screws screws and will drop out of the blend door splined shaft. The splined shaft and input on the door is plastic so don't torque the motor when removing it. Carefully insert a flat head screw driver to the blend door door input where the shaft was and turn it to ensure the door moves, if it doesn't then.....you have to yank the dash and I am sorry. Replace or test the motor then reinstall.