smelling anti freeze

I have a 2000 Jimmy and as I was driving last night I could smell anti freeze and my front window was getting very foggy I turned on my defrost but it took a long time for the windows to clear. As long as I ran my heater on cool the smell went away and I had to have it on high. I tried to turn it down to 1 but the smell came back but not as strong as it first did. Is this my heater core, also I just put in a new altenator within the last week. Any help would be greatly appreciated. O.k now I just went for a drive and my windows didn't fog, but I could still smell the anti freeze. I also check my rad and it is full, so I'm not leaking any. I have no drips of any inside the truck and I was always under the impression that if your heater core was no good your windows would fog all the time.So with that thought I'm completely lost on the problem.

Thanks to all your wise advice

Sounds like a heater core to me. It probably is just a tiny leak that will get worse as time goes along. Will eventually start leaking into your floor. Might get a pressure test to see if you can d/c that or perhaps a leak somewhere else.

Unfortunately it sure sounds/smells like your heater core.It is 5.5 to 6 hour job.Did mine last month.Part was 100.Can.You could wait till it leaks but it will smell and fog your windows.

Unfortunately it sure sounds/smells like your heater core.It is 5.5 to 6 hour job.Did mine last month.Part was 100.Can.You could wait till it leaks but it will smell and fog your windows.


Thanks for such a quick reply but whereabouts is it located I've read that I have to remove my dash is that true.

Ours did the same thing and my heater core is leaking. We got the dash out (and yes you Have to pull the dash) and could see the heater core through the box to tell it was leaking but can't get the box open to get the heater core out. I would advise you to spend the money to get it fixed by a professional or pull the heater core hoses from the firewall and join them together to bypass the heater core all together. If you bypass it you won't have heat, but your engine could run hot if you leave the leak. Also, I have read that the Dexcool is really bad for your system and if you can get someone to clean your system completely of Dexcool and change it to the green stuff you will be better off in the long run.

Good Luck

I imagine it is your heater core. It only takes a very small leak to smell antifreeze. Mine was a gusher so it was easy to identify. Per the other posters it was a mother bear to get out. I did get a new core for about 25.00. Shop around a bit if you are going to try and do this your self. Good luck

Thanks for such a quick reply but whereabouts is it located I've read that I have to remove my dash is that true.


Yep, gotta pull the dash (or atleast swing out the right side...)