2nd Gen Non-Engine/Transmission Antifreeze leak in heater core?

[Junior]

OK guys i think my antifreeze is leaking in my heater core. I see no leaks in the engine bay but once the truck gets to operating temps. i start smelling the antifreeze inside the truck. also the windows start fogging up with a light haze but you can still see out of them. i have cleaned the windows numerous times and it helps but the haze still develops when the heat is in. no matter if defrosters are on or not.

Question is how would i look into this without taking the heater core out from under the dash? is there any way of trouble shooting it in the truck?

i have only just started noticing this due to using the heat with the colder temps again.

 

[DieselDoghouse]

Provided your antifreeze has fluorescent dye in it (most due) you could go under the firewall to the condensate drain with an ultraviolet lamp. A glow there could have come from only 2 sources: the UV dye of r134a, in which your a/c was malfunctioning, or a coolant leak dripping out. Straight condensate water should not lite up with a black light.
Good luck!

 

[kentdiesel]

If you don't find a way to see into the heater box for antifreeze don't worry. The anti-freeze will find its way out the heater duct soon. After my truck began hazing the windshield and I started smelling anti-freeze a month or so later it was dripping out of the floor duct on the passenger side. Ruined the carpet. Took me an entire day to replace the heater core.

 

[Junior]

This is not sounding good. def. not what i wanted to hear.





are the heater hoses going into the core clamps on engine side or inside the truck?

 

[HHhuntitall]

Clamped on engine side. If you go back through the threads or back issues of TDR, you'll find several articles, and even a good write up on how to do this. It's not fun. I won't do it on customer's trucks, it's too time consuming. I start by removing the front seats... ... but I'm an ogre. Some have done it by letting the dash fall forward and reaching the A/C box from the passenger side floor.

 

[GrantP]

About 4 years ago I had the same problem on my 97, an oily film on the inside of the windshield and the smell of antifreeze. It slowly progressed to a small drip of antifreeze out of the passenger side floor heater vent.

Joe Donnelly did a great write up on this procedure, all tools required, step by step instructions etc. I had that issue flipped open on my workbench during the job, it was a huge help. Since the dash was mostly disassembled for the procedure anyway I also replaced my cracked dash along with the heater core. The procedure was a full days work and zero fun with lots of old brittle plastic to be careful with. It's definitely one of those jobs where the labor is far more than the part cost.

 

[Moe]

Any idea on using some sort of stop leak to close the cracked heater core until I can replace it this spring. I dont really want to plug up the block, but its too cold to tear the dash out. Thanks, Moe

 

[HHhuntitall]

I've had people tell me they've used Bar's Stop Leak in it, and it lasted awhile... . I don't like that stuff, but if you need to get by for a while, it might make it last a few..... It sure makes the coolant nasty.

 

[ed9824v]

I have been using the powder leak stop and it is the cheapest works pretty good.

 

[jleons]

Hello
Last year heading back from a trip to Kansas, noticed your same issues; dripping anti-freeze on the passenger side floor. Stoped in at purchased a can of BG - Universal Cooling System Sealer, and drove home to NM, without any further sign's of a leak.
Will have to make the repair sometime, but it's still dry.
Good luck
JL

 

[Cosmo]

Removing the seats? Seems excessive. Heater cores aren't too bad, but in older Dodges (2nd gen, early 3rd gen now) the dashboards are apt to shatter. My heater core went out early this winter and now I don't have a dash - I've got an instrument cluster and an airbag module/glovebox, and a molded carpet cover with nothing under it.

It's a good 6-8 hour project, and if you've got A/C you'll need to get the system sucked down and when you put it back together, replace the o-rings on the A/C lines.

 

[HHhuntitall]

Removing the seats? Seems excessive. Heater cores aren't too bad, but in older Dodges (2nd gen, early 3rd gen now) the dashboards are apt to shatter. My heater core went out early this winter and now I don't have a dash - I've got an instrument cluster and an airbag module/glovebox, and a molded carpet cover with nothing under it.



It's a good 6-8 hour project, and if you've got A/C you'll need to get the system sucked down and when you put it back together, replace the o-rings on the A/C lines.

Yeah, I only remove the seats due to my size... . I can't get in there, otherwise... . AHHH, the busted dash!! Another reason I don't want to them for customers!!! Nothing like saying, "Yeah, we got your leak fixed, but you're not going to like it... . " Or, "That's gonna be $350 in parts... . $61 for the heater core, the rest is for consumables... . Oh, and a new dash if that one breaks. " Talk about getting a "WTF?" look from a customer!!! :-laf

 

[GAmes]

... ... if you've got A/C you'll need to get the system sucked down and when you put it back together, replace the o-rings on the A/C lines.

The magazine in two issues has given instructions how to replace the heater core without having to do anything to the A/C.

 

[S.Morris]

The powdered type stopleak... ..... that GM sells with OEM part #. (can't remember it) works absolutely amazing miracles and in my experience lasts as long as you don't change the antifreeze (I know its not the correct way but sometimes in a bind... )

It says on the box that it is factory installed in ALL GM aluminum blocks... .....

 

[Cosmo]

Yeah, I only remove the seats due to my size... . I can't get in there, otherwise... . AHHH, the busted dash!! Another reason I don't want to them for customers!!! Nothing like saying, "Yeah, we got your leak fixed, but you're not going to like it... . " Or, "That's gonna be $350 in parts... . $61 for the heater core, the rest is for consumables... . Oh, and a new dash if that one breaks. " Talk about getting a "WTF?" look from a customer!!! :-laf

Yeah. No kidding. But it's something you've GOT to talk about before going in... .

The magazine in two issues has given instructions how to replace the heater core without having to do anything to the A/C.

I haven't seen the write-ups. I haven't done enough of them to know the heater boxes from memory, and the last one I did was a 3rd gen, but I'm having a hard time envisioning it without yanking the whole case away from the firewall, which would require disconnecting the A/C.

I'll see if I can find the write-up.

 

[Cosmo]

The powdered type stopleak... ..... that GM sells with OEM part #. (can't remember it) works absolutely amazing miracles and in my experience lasts as long as you don't change the antifreeze (I know its not the correct way but sometimes in a bind... )
It says on the box that it is factory installed in ALL GM aluminum blocks... .....

I'm not sure about the FB motors, but any time the coolant is drained/flushed on EJ motors at a Subaru dealership, a bottle of stop-leak gets dumped in.