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Old Apr 15, 2008 | 10:00 PM
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Default replacing the heater core

ok im in need of swapping out my heater core and i dont have the first clue but im guessing its the kind of job that is worth paying a stealership to do. any ideas? is it doable or roughly what do you thjink they charge?

Bill
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Old Apr 15, 2008 | 10:37 PM
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I have not had to do this on my C5 .... but had to replace the heater core on my GMC Jimmy a couple of years ago ..... it is a MAJOR piece of work .......

Depends on where you want to spend your time/money ..... the C5 heater core is buried deep inside the vehicle's "dashboard" and you need to spend a lot of time removing parts to get to the basic system.

What makes you think you need to replace the heater core ???? GM designed them so that while they are a freakin bi**h to replace, the need to do it should be small .....


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Old Apr 16, 2008 | 12:08 AM
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it started pouring water into my pass. floorboard. looks like its off to the dealership hopefully i dont get bent over.
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Old Apr 16, 2008 | 12:43 AM
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WATER OR ANTIFREEZE ?????????????????????????????????

If its just water,,,,,,you have a plugged HVAC air box drain!!!!

If it is truely DEXCOOL antifreeze, then you either have a LOT of work to do OR a LOT of money to pay the dealer. In my honest opinion,,,its most likely a clogged drain and that takes 30 min to fix!
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Old Apr 16, 2008 | 01:26 AM
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^^^^^^ BTDT! Don't forget to check the udders
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Old Apr 16, 2008 | 07:53 AM
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i'de bet its water from the plugged udders.
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Old Apr 16, 2008 | 09:06 AM
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Originally Posted by BlackZ06
I
Depends on where you want to spend your time/money ..... the C5 heater core is buried deep inside the vehicle's "dashboard" and you need to spend a lot of time removing parts to get to the basic system.


I was thinking that you have to replace the heater core on a C5 from the engine compartment, so it would required removing the intake manifold. Not an impossible job, but would require time and patience.
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Old Apr 16, 2008 | 09:15 AM
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Pulling the dashboard is not impossible, just take your time. Now depending on what else you have to remove after the dashpad....could take a while -- if you don't need your heater you may be able to just bypass the heater core. At least until you can get it repaired.

But first take Bill Curlee's advice and check if its water from HVAC drain (he's the man on advice like this!). You can tell my smell.
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Old Apr 16, 2008 | 10:49 AM
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My 02 heater core let go last year. I just bypassed the heater. I still haven't repaired it. I plan on doing a head and cam swap later this year, I may do it then when the intake is off.

Mike V
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Old Apr 17, 2008 | 12:56 AM
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Here are some pictures of the HVAC drain. If it is clogged, water/condensation from AC or defroster operation will back up and spill into the passengers foot well.



The small crimp will clog up and cause the problem:




Here is where it located on the fire wall:





You can almost see it from the top and if you have skinney arms just touch it:





If you have a stock C5, reaching it from under the car is a snap. If you have headers, it a royal pain in the %$#.

BC
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Old Apr 17, 2008 | 09:07 AM
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Originally Posted by MikeV
My 02 heater core let go last year. I just bypassed the heater. I still haven't repaired it. I plan on doing a head and cam swap later this year, I may do it then when the intake is off.

Mike V


If you think your going to replace your heater core once you remove your intake manifold, your sadly mistaken.

I replaced a windshield frame and firewall on an 04 coupe, the first thing that goes into the car when assembling the dash components is the HVAC unit. If you have to replace your heater core, it's a full day just to disassemble the car, remove the HVAC unit and replace the heater core. If your good you might have some of the install started at the edn of a full day wrenching.
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Old Apr 17, 2008 | 10:25 PM
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Thanks guys im hoping its a simple drain but what has me worried is, i already bypassed the heater core and it stoppped leaking. could it still be the drain?
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Old Apr 17, 2008 | 10:59 PM
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If its a condensate drain clog,,,the only time its going to leak is if you have the AC on and its a humid day. It also needs to be running for a while. Then you will know if its the HVAC condensate drain.

Is the liquid in the passengers foot well clear or orange stickey and smelly??

BC
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Old Apr 17, 2008 | 11:52 PM
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Originally Posted by OneFastS15
Thanks guys im hoping its a simple drain but what has me worried is, i already bypassed the heater core and it stoppped leaking. could it still be the drain?
As intimidating as it sounds, pulling the dash isn't that big a deal. You can have it lying at your feet in 30-45min. There plenty of step by step write ups on the forum for doing it. I did it on mine when doing the HUD conversion, and again on my Captains '00coupe. Let me know if you need the write up and I'll post the link, or send you the one I have. All you'll need is a 7mm, 10mm, and a t-20 torx. It's really easy for a novice to tackle. Save the bucks- and don't let another fella touch your baby if you can avoid it!!!
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Old Apr 18, 2008 | 01:26 AM
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Originally Posted by 97C5owner
As intimidating as it sounds, pulling the dash isn't that big a deal. You can have it lying at your feet in 30-45min. There plenty of step by step write ups on the forum for doing it. I did it on mine when doing the HUD conversion, and again on my Captains '00coupe. Let me know if you need the write up and I'll post the link, or send you the one I have. All you'll need is a 7mm, 10mm, and a t-20 torx. It's really easy for a novice to tackle. Save the bucks- and don't let another fella touch your baby if you can avoid it!!!

You might want to read what runamuk posted above ..... while it is not as mechanically challenging as say, rebuilding your engine .... you will NOT have the HVAC module out in 30 to 45 minutes .....

As pointed out, the HVAC module is about the first part put into the car and the rest of the interior is basically built around it.

The "instructions" for removing the HVAC unit are 9 pages in the HVAC section of the Service Manual, but some instructions are things like "Remove the IP Center support bracket" which means you go to the IP section of the manual and read the 4 pages for that .... which by the way is the "bracket" that contains the HVAC control unit, Stereo, and yaw rate sensor.

Basically the ENTIRE dashboard, instruments, controls .... EVERYTHING has to be removed to get the HVAC module out .... along with (in the engine compartment) the intake manifold and some of the AIR system piping.

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Old Apr 18, 2008 | 01:40 AM
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just a comment, i came across that HVAC drain boot when i was pulling my engine and not knowing what it is, it kind of looks like a wire should be coming out of it... so, not realizing what it is... I consulted the corvette forum. it was clarified that it drains any condensate from the A/C condenser... and i was recommended to verify that it was completely clean of debris since i was working right there, becuase they are known to plug and back up water into your interior!

john

**edit: of course its not safe, nor recommended but if you touch your finger to the fluid on your floor and taste it, if its sugary and sweet its dextron. don't forget to spit.

Last edited by Bloodvette; Apr 18, 2008 at 01:47 AM.
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Old Apr 18, 2008 | 02:28 AM
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Originally Posted by Bloodvette
just a comment, ..... (edited out) .....

john

**edit: of course its not safe, nor recommended but if you touch your finger to the fluid on your floor and taste it, if its sugary and sweet its dextron. don't forget to spit.


I always try and emphasize .... when dealing with engine coolant (Dexron ... Prestone .... whatever) people need to be very aware that a primary ingredient is Ethylene Glycol.

Ethylene Glycol is DANGEROUS because it tastes sweet, and is a POISON.

People need to be very careful to keep children and pets away from engine coolant. Engine coolant is a deadly poison. Treat it that way.

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Old Apr 18, 2008 | 08:22 AM
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Hey Bill, could you give a little more info on the description of the 2 small pics which show the udder attached to the firewall? What angle are those pictures taken from?
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Old Apr 18, 2008 | 09:51 AM
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Originally Posted by OneFastS15
Thanks guys im hoping its a simple drain but what has me worried is, i already bypassed the heater core and it stoppped leaking. could it still be the drain?
Leaking what?? You still have not confirmed if it is water or coolant....
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Old Apr 18, 2008 | 11:34 AM
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I know mine is definitely coolant. I have bypassed the heater for the past year until I do my head cam swap.

Mike V
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