awork

I have a 97 Cherokee. Since it has started cooling off I used the heater finally the other day. When it first starts running it has a sweet smell (antifreeze). After a few seconds of it running the smell goes away. The heat is warm and have had no issues with it not working.
Is the heater core on its way out or could there be another issue?

Thanks

rockstomper92yj

I would look to see if you have leaks anywhere else first. Is you floor mat on the passenger side damp?

cliffpenick

Do you smell that inside the jeep? If so then yes your heater core is probably starting to leak. If you put the defrost on, does it fog the windshield?

ih8cornnuts

Also pay attention to see if you have a fine mist coming out of your vents. This plus the sweet smell usually means that entire dash is coming out. There are threads here which recommend replacing all the components in that "heater box" including the AC evap and fan. I did mine 2 years ago this month.

seanward10407

all of these suggestions are exactly how to diagnose a leaking heater core. Let me know if you have trouble fixing this issue, I had to do it on a Dakota, and it is 10X worse than on a jeep.

Vincenza V

I have a 99', same symptoms. I can't afford to get the HC replaced right now, so I had a brass bypass where the inlet/outlet meet the firewall. Though I'm in FL. It doesn't get that cold here.

The defrost vent area kept misting the windshield bad before I bypassed it.

s14unimog

Word from the wise, if you ever have to bypass your heatercore, DO NOT loop the lines together. You are essentially dumping outlet water to your inlet water. Block them off separately. Trust me on this one.

To the OP, does sound like you have a leak, be sure to mind your floor pans. You can leak gallons down there unknowingly and the sound deadening will only hold the moisture against the metal. Bad news for a Jeep.

Pulling the dash isn't terrible. Check out my thread here on when I replaced mine. Might be helpful to ya.

https://www.cherokeeforum.com/f2/coo...k-cabin-83928/

Ye Ol' Cherokee

What do you mean by dont loop the lines together? I cut both of my heater lines and connected them using a preshaped 180* elbow hose.

s14unimog

THAT. Don't do that. You're cooling will work MUCH more efficiently if they're simply blocked off separately. Trust me, I've thoroughly vetted this.