Antifreeze odor with heater on?

dale5150

TJ Enthusiast
Joined
Apr 7, 2020
Messages
109
Location
ky
I flushed my coolant this summer and am not loosing any that I can tell. However now that it has gotten cooler I have used the heat and get an antifreeze odor. I dont see any leaks anywhere. Heater core? Hard to replace?
 
Yes most likely heater core. The dash has to come out, so "hard" is relative depending on how much automotive work you do. It's not a terrible job, just time consuming. Took me about a day & a half. It's a straight forward job, just lots of little screws & having to remember the right way to get the harnesses connected back up.

You'll also have to evac the AC system because the evaporator sits next to the heater core.

I was getting that coolant smell for about a year, when I opened the HVAC box it was all gunked up with shit. Had a teensy pinole leak that just misted, not enough to drip visible coolant but enough to saturate the area over time.
 
  • Like
Reactions: SvtLdr
I flushed my coolant this summer and am not loosing any that I can tell. However now that it has gotten cooler I have used the heat and get an antifreeze odor. I dont see any leaks anywhere. Heater core? Hard to replace?
Same with me so i flushed it and bypassed it but i live in Texas and don't drive it much in the winter.
 
I flushed my coolant this summer and am not loosing any that I can tell. However now that it has gotten cooler I have used the heat and get an antifreeze odor. I dont see any leaks anywhere. Heater core? Hard to replace?
Lots of write ups, and probably videos too, but there are also some shortcuts if you read through them.
I didn't remove the entire dash, just disconnected enough to tie it up to the roll bar.
I didn't evac. and refill the AC either.
 
  • Like
Reactions: SvtLdr
I didn't evac. and refill the AC either.
Were you able to replace the heater core without removing the evaporator? I'm staring down the barrel of this job right now also...
 
Were you able to replace the heater core without removing the evaporator? I'm staring down the barrel of this job right now also...
I didn't remove anything I didn't absolutely have to. I know some replace the evaporator so you don't have to tear apart a second time. It was a long time ago, but I do remember capping the AC lines after I unhooked them. It worked fine when I put it all back together.
A couple of tips: remove front seats and center console, and cover steering column so you don't scratch it.
 
  • Like
Reactions: SvtLdr
So far I would rate jeep taking the jeep apart as follows: Keep in mind it is not fully taken apart
I am rating from biggest PIA to easiest

1. Dash and Heater Core this required a copious amounts of whiskey, cussing, and I am going to by gawd kill the engineer who thought this shit up= 11 wrenches and a 5th of Wild turkey 101 and where is my goddamn gun

2 Roll bar and that would be a close run for number one, again when will people learn ANTISEIZE ANTISEIZE and ANTISEIZE and again what dumbass engineer thought giant torx drive bolts were a good idea =10 wrenches 1 welder (so you can weld bolts on to those MOther @#$%%^&&** tork drive bolt heads and knock them loose with a 3/4 drive impact) and a 5th of Wild turkey 101 and where is my goddamn gun

3a. Gas Tank, not too bad working under it laying on your back and trying to unhook all those quick connect lines about 5 wrences and a 6 pack of Shiner

3b Leak detection pump unit 2 wrenches and a tall boy

4. Axles, Diffs, Brakes, Driveshaft, Suspension, coil springs, Ball joints, Unit bearings Seats and other interior components. About three wrenches and several 12 packs of Shiner and a lot of satisfaction.

There are some really good youtube college of knowledge videos for the Heater core watch them
 
There is a Plastic cover/duct behind the Valve cover on the fire wall it has one nut on top of the cover and one underneath it on the same stud
IMG_4295 (1).JPG

I think its that hole at the top of and just to the right of the gear shifter
 
  • Like
Reactions: SvtLdr
Sounds like that is what is going on then. It is not a daily driver and it is driven less in cooler weather so I will see how long I can stand it.
 
Sounds like that is what is going on then. It is not a daily driver and it is driven less in cooler weather so I will see how long I can stand it.
I'm having the same symptoms inside my Jeep. I'm also getting an oily haze that collects on the windshield when the vents are blowing warm air. Switching over to the defrost setting will overcome this condition after what seems like an eternity. The swamp-like atmosphere has been going on for a couple weeks now and I've recently developed a tiny coolant drip collecting in the passenger side foot well. After finally deciding to face the music, I proceeded to bypass the heater core - all the problems have now been solved. Except I created a new problem... no heat. 😒

Luckily my Jeep is only a seasonal vehicle. We've had a few morning in the upper 20's and I've really missed having heat. I have one more trail ride to attend this weekend and then I'll be storing it for the winter. My concern was that the tiny pin hole in the heater core might get worse at some point while driving, rendering me with a larger coolant leak.