safemode

iTrader: (1)

Well, a few days ago I overheated. I bought a new thermostat to fix that problem. My old one was caked with dexcool crud and rust. Unfortunately, soon after this fix i noticed a really nasty smell and misty smoke coming from my air vents in the car. I couldn't find any smoke coming from in the engine bay related to coolant burning off. The smell, sorta reminded me of coolant, so the only logical conclusion was that it was the heater core. So i researched it up and found that I could replace the heatercore from underneath the passenger compartment without taking apart the whole dash.

So I bought a new heatercore for 35 bucks at autozone and went to work. The only way this job only takes an hour or so to do is if you dont have any of the hard to reach screws in anymore. Anyway, after seriously screwing up my hand getting all the screws out I got the core out and dumped it. Only orange cruddy water came out. (my coolant is green everywhere else). success, i thought. My heatercore hoses were likewise caked with dexcool residue and rust. I replaced the one i could get to, but apparently GM engineers are sadistic A-holes and put the other hose at the back of the engine underneath 10 other hoses, the firewall and AC equipment and blah. I can't wait until i throw all this crap out and drop an electric motor in.

Anyway, i get the new heatercore in and button everything back up (minus that retarded top screw). I get new coolant and fill the radiator back up, as well as my overflow. Turn the car on and voila, more smoke coming up out of the vents. So, obviously by now, I'm ready to flip out. The only other thing i can think of is electrical fire. Which is strange, because i dont have any electrical issues. So i drop the driver side under-dash cover. Nothing. I then take the bezel off the center console and pull the heater/ac control unit.

And there it is. The center electrical connector is melted as is the black plastic circle thing it's connected into (which was what was slowly burning, producing the smoke). The blower motor electrical connector is also melted. So both elecrical connections going into the unit are melting and the things they plug into are also melting and burning.

Sweet. I just replaced a perfectly functioning, albeit very nasty, heater core when the problem was a 5 minute job of removing the heater/ac control unit and disconnecting the electrical plugs and pulling the fuse from the fuse box. I usually would be able to tell the difference between plastic burning and coolant burning, but after dealing with so many coolant issues this past month, i guess everything started smelling like burning coolant to me.

So i guess the moral of the story is to investigate everything else before attempting to replace the heatercore. On the upside though, I do now have a very good flowing heatercore now. The car runs at 180 degrees thanks to the 180 degree thermostat, and i almost never have to turn the fan on anymore. I dont know how many hours i spent replacing the heatercore, but i do know it was 4 hours after i started that i was pulling the fuse from the fuse box to stop the electrical fire from continuing in the heater/ac control unit. At least i didn't barely have anything i needed to put back together, since i only took out a couple things.

cameron7710

dam that sucks that u replace that and u didnt need to cause those things r a pain in the *** to replace.but at least u did find the problem

kcb37

I understand your frustration, but at the same time sounds like it didn't hurt to do the heater core either.

mario82z28

That does suck been there and done that except i just went ahead and pulled the whole dash out of mine,that was the biggest pain in a** thing i've ever done on the car but mine was out nothing like getting antifreeze all over your new carpet and windshield your second run out, so at least that didnt happen to ya

Gordiggz

Heater core on my old formula went. 10 minutes, one pipe and two hose clamps later and problem solved. Oh to be 17 and jimmy-rig everything without remorse would be great wouldn't it?

80schild

iTrader: (5)

If it was rusty it was probably just a matter of time. Mine is not leaking but I'm thinking of replacing it anyways before putting in new carpet.

88 350 tpi formula

iTrader: (9)

the top screw is nothing. sounds like you were too upset.(nothing is worse while doing a job. ) just a light and a long ext. that's it.

safemode

iTrader: (1)

the problem with the extension is that you have to have the right sized extension, too little and it's no use, too long and you hit the front of the dash. There is no way to put two hands on it at once, and going in from below leaves you with an incredibly little area to play with. Going in from up top isn't that bad, but you will still fight it.

Also, what would a light do when the screw is completely out of sight no matter what direction you look from? you're going in blind, no matter how bright it is.

The problem i had the most was that the tools i had were either too big or too small. I'm fairly sure GM does that crap intentionally.

dstss

I had to change my core a few months ago after the old one threw up on my new carpeting. What a pain in the rear. I couldn't how to do it with out taking the dash apart. Had it all back together and realized the vents inside didn't line up right. Had to take the dash all down again. Hopefully I wont have to do it again for another 100k miles.