Likely Heater Core Failure
 

I've owned my current 1991 ZR-1 for just short of 20 years. It currently has almost 18K miles and I've maintained it since it had ~2K. It had less than 7K miles for the first 15 years. The balance of mileage has been added in the last 5 to 6 years. As of today, I've got antifreeze smelling vapor condensing on the windshield and antifreeze in the passenger plastic foot wells. I'm thinking it's time for a heater core.

I would like to get some input from someone who has installed a heater core in their ZR-1. Specifically:

1) Did you remove the dash or were you able to get to everything by removing the glove box and lower passenger-side panel ? I think there are a couple of bolts that will be tough to get to without removing the dash. I'm planning on using an inspection camera in order to get a socket on them.

2) Is the OE heater core still available and if not, is there one aftermarket manufacturer known to be "high quality" and form, fit, and functionally interchangable ?

3) Any other words of wisdom or suggestions ?

The damage is done but the cooling fluid was changed every 3 to 4 years with the proper antifreeze and distilled water. In the winter the car was garaged in spaces heated enough to take the chill off and in the summer, air conditioned enough to dry the air and keep the temperature below 85 F. Any thoughts on why this heater core might have crapped out ?

Re: Likely Heater Core Failure
 

What makes you think it has failed? Is it leaking coolant into passenger side footwell?
I have never replaced late C4 heater core but when Paul Farrance had his replaced Dan (Y-me), I believe, removed the dash pad to do the work.

Re: Likely Heater Core Failure
 

Everything I read says you have to go in from the Dash and it is NOT fun. Take plenty photos for us if you do it.

Removed Heater Core

Re: Likely Heater Core Failure
 

But then, may be not necessary to pull the dash pad.
http://www.c4vetteregistry.com/vrfor...at-bad/406397/

Re: Likely Heater Core Failure
 

Thanks. I saw that thread and a few others. Looks like it can be done but either way it does not look like a fun job.

Fortunately I have those carpeted plastic "boots" that lined the footwells but yes, I had coolant in the passenger footwell. The defroster was also blowing vapor that smelled like coolant onto the windshied.

Anyone have any thoughts on aluminum vs copper heater core?

Re: Likely Heater Core Failure
 

I'll do my best ! Need to get it done. In the Washington area, this is the best time of the year to enjoy the car!

Re: Likely Heater Core Failure
 

Having been there and done that its easier with the dash off on the 90-93 MYs. Best suggestion I can offer is to remove the targa top and pull the passenger seat to allow you to lay on your back and get some room to do the job.

I wont kid you its a complete PITA and a labor intensive job. I have not done this on the 94-95 ZR-1 since I havent owned one yet but the passenger airbag just adds to the complexity however its a simple unplug and move out of the way process.

Take a lot of pictures for reference along the way. If you do pull the dash be mindful of the weak area along the window on the passenger side which is very thin and can be brittle. It is best to have another person hold the drivers side of the dash while you negoitate this side out of the car.

Use this as an oppourtunity to clean the vents or consider a dash leather wrap upgrade opportunity :). Repair the foamy felts that surround the AC vents. I used to joke about the heater core being GM part 000000000001A and then the GM guys designed the rest of the C4 around it. Some GM Engineer is still prob laughing his AZZ off. GC

Re: Likely Heater Core Failure
 

I don't know that I wouldn't consider a repair VS. the replacement of with the current product offerings. Not in your neighborhood but in years past (many) I used this shop in Landover for some unusual repairs. SMITTY'S WELDING AND RADIATOR if the management and employee staff is the same might be worth contacting OR perhaps there's shops in your area that might come with recommendations. SMITTY'S wasn't close but I sent all that I had to them and if they mentioned a fix/repair possible it was always done VS. the purchase.

A bypass of the heater core for the season? Maybe

New I'd maybe consider SPECTRA - a very long time ago this was a Canadian Corp that did engine oil pans and higher quality than most radiators etc. I used their products for many years. I'm quite sure the company has certainly evolved and possibly "consumed" with maybe the cost-cutting adventures. Who knows? They do seem to offer or at least I was able to get a cross-reference using some tools to what was/is their product. A 94494 would be their part # if they still offer it.

Re: Likely Heater Core Failure
 

I would not EVER consider a repair on the Heater Core. Other than bypass a OEM quality factory replacement is the only way forward IMHO.

Could it be done? Yes as WV states but I personally would never do it. :)

Re: Likely Heater Core Failure
 

Hi Scott, I am busy with rehab'ing a rental property, but if you let me know when you are going to work on it, I will try to come down to your area and help. Nelson has experience pulling the dash pad and I am sure he would be glad to help as well.

I have a coolant system pressure tester that you can borrow if you want to try and verify a heater core leak.

Jim
443-244-1347