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Replacing heater core

54K views 43 replies 23 participants last post by  shulz_79 
#1 ·
Ok, 05 TB LS v6

Since it has started getting colder out I have been using the heat. Found out I have that lovely coolant smell in my car when I am using the dash vent. I have not noticed it using the defrosters or the floor heat. Well my spidy senses tell me that my heater core is leaking. I know if I used stop leak it will be useless, so my next choice is replacing it. I can get a new one for 71.00 with shipping from GM parts Direct. Well this brings me to the question WTF is involved with replacing it.
Anyone happen to have step by step instruction on replacing it. Or should I just take it to a dealer, which I am trying to avoid.

Any help greatly appreciated.
:thx
 
#2 ·
Don't know about the TV, but my Jimmy was a b****. :bonk: Had to remove the driver's seat, drop the steering column to the floor, and take the entire dashboard off. Took about 8-9 hours by myself, but it was worth the savings. Had about $60 in to it (including the Haynes), but the fix-em-up guy wanted $800+.:hissy:

It is doable, but the best advice I can give you is BUY A HAYNES (or similar) manual and read that. Also, make sure you keep track of EVERY single bolt, etc... that you remove. I had a few left over when I was done with mine, and could have avoided that if I took my time and marked everything. Hope this helps, and good luck:thumbsup:
 
#4 ·
Seems like it would be early for an '05 to have a heater core problem. With no leak on the floor, how do you know it is not a leak under the hood? Your vents could be pulling in the smell. Also, did you recently put coolant in? If overfilled, it could be the overflow. For such a difficult job, I would try to rule out the simpler stuff.
 
#5 ·
Ok, I have not touched the coolant system and or any hoses attached to it since last winter or early spring this year.
It has me confused why I only get the smell from the panel vents also and not anywhere else, but if I move temp controls all the way to cold, no smell from the panel vents. I have to remeber to check the carpet in the front to see it has a damp feeling. I have not noticed and puddles or anything under the truck. the smell seems to go away at idle, sat in my truck at lunch yesterday, smelled it going to pick up lunch, and coming back, but if I remember after about 20 mins of idleing with the heat on the smell went away.

I do not have access to a pressure tester, I guess I can rent one from the zone....
 
#7 ·
Sorry guys I have been busy between working and finishing up school.
Ok back to my problem, it is the front heater core, It has been nice here so I have not been using the heat. but come friday after the TB warmed up I turned the heat up and I had steam coming out of only the two driver side vents.... So far nothing is wet inside the truck, carpeting is dry, and I ran my hand along the firewall on the passenger side and I didnt feel nothing wet..... So I hope it can hold out for a few more weeks. Right now I am just using the the passenger side heat while leaving the drive's side on cold.... this stops the antifreeze smell
 
#41 ·
I'm not hearing anything, concerning possible engine overheating.

Seems the thread continues to speak of antifreeze smell, but always keep in mind that an antifreeze leak, no matter where, will affect the overall operation of the cooling system.

Lose too much coolant, then continue to drive, will lead to engine problems.

Monitor your coolant level, as you drive with the leaking heater core !
 
#10 ·
Ok well scratch what I have said previously.... :(
I now get the coolant smell thru all the vents and windshield if fogging badly. I ordered a new core today from gmpartsdirect so I should receive it sometime next week.... I know what I will be doing next weekend WOOT!!!

I have had the TB for almost 2 years now, and this is my second winter with it, so hey all is good $h^t happens right?!!!?
 
#15 ·
So chigo, did you ever swap out that heater core? The reason I ask is that now I have to do it! :mad::mad::mad: I have that sweet smell inside and fogging up the passenger side window and windshield, and not from a trip to lover's lane. Coolant leak from the drain is getting worse after only 2 days, damn!

Oh, and tomorrow just may be the coldest day on record here. I'm not looking forward to this. I have the Hayne's manual. Its pretty funny that for a DIY book, the first paragraph strongly suggests not doing this yourself, prolly why we don't have a lot of pics here, ya think?
 
#18 ·
Glad it worked out for you Filthy.

After lurking on here for a few weeks and not seeing much info on heater core replacements I chickened out. 10 hours in my 45 degree garage wasn't looking too promising, even with Chiltons, Haynes and the Factory Service Manual at my disposal. I'm glad I had it done.

$618.99 at my Chevy Dealership....I just picked it up hours ago. No more sweet smell, and best of all no more foggy greasy windows.
 
#19 ·
Glad its done! So a week ago I removed the center console, and rocker panel plastic cover. Then with a razor, I cut the passenger side carpeting and the batting underneath to separate it from the driver's side. There had to be 2 quarts of coolant soaked into the carpet and laying in the sump.

I took the whole mess outside and hosed it down until the water stopped running green. Hung it all out to dry for a few days and it all went back okay.

Now its done. I hope. When I accelerate I can hear coolant gurgling through the core. Trapped air? I dunno but the heater works fine.
 
#21 ·
green coolant?
Should be red.

I wonder if the green stuff helped deteriorate your heater core???
The red stuff has anti corrosion properties for the aluminum parts.
 
#23 ·
When you switch from Dexcool to the green stuff, if the flush is not done as complete as possible, the mixture will accelerate corrosion. The advantage to Dexcool, is if it starts to change color,ie: from pink to brown or orange, you know you have a problem. The introduction of air or other fluids initiates this color change. You can then do an oil analysis to help figure out what is getting in there.
 
#25 · (Edited)
another related question

I am new to this forum, and have a question. My girlfriend has a 2005 Trailblazer with a rear heater and air conditioner. On Saturday, the coolant started leaking at a very high rate from the rear drain and the engine overheated. Is there a separate heater core in the rear, and if so, is it as labor intensive and expensive to repair?
 
#26 ·
Yes. Separate heater core. Could be hose or core problems. I think it's relatively easy to swap. Right rear side, but you knew that already. Certainly easier than the AC evaporator, which takes special equipment. And certainly not as difficult as getting the dash out to work on the front heater core.

If you're going to do it yourself, start taking things apart. If you have a trusted independent mechanic, call them.

Temporarily, if you have no time right away and the hoses are OK, just get a pipe to splice the heater core input hose to the output, and bypass the leak and fill the coolant back up and give blankets to any rear seat passengers so they don't shiver. :cool:
 
#28 ·
2005 Trailblazer EXT.

OMG. Now that I have had this experience I think I can do about anything. If you plan on doing this job be prepared. Basically you have to take out everything and when I say everything I mean everything. The only items left were my wiring harness and steering column. It became a two day job and I felt very overwelmed. Its all back together and everything works. That was the stressful part, making sure all the wires got hooked back up. I good way to ensure proper reconstruction take lots of pics. I will post pics later.
 
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