Heater Core Removal From Engine Bay?
Thread Starter
2nd Gear
Joined: Dec 2011
Posts: 2
Likes: 0
Heater Core Removal From Engine Bay?
While the engine in my '91 6-speed is being rebuilt, I would like to replace the heater core. Based on lots of other posts about this subject, I know how time-consuming a task it is from inside the passenger compartment, but I have never read whether-or-not it's possible to do from inside the engine compartment. Anyone out there have an answer to this question?
Thanks a million!
Thanks a million!
Moderator Emeritus
Joined: Jun 2002
Posts: 46,133
Likes: 111
From: Maryville Tn
CI 5 thru 12 Veteran
St. Jude Donor '09 thru '23
NCM Sinkhole Donor
The easiest way to remove it is to remove the passenger seat and work from the bottom. See RonsRed88 post on the procedure. Followed it to the letter when I had my '85.
Pro
Joined: Aug 2001
Posts: 617
Likes: 14
From: Loudon, TN
Not with the new style dash. There is no way you can access the screws at the top of the heater housing from the bottom. You have to take the dash off and a bunch of braces have to come out to remove the housing. The heat/AC duct has to be taken loose to get at the screws on the top of the housing. It is not fun.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Notice it says 91-up was revised to allow heater core service from the engine bay.
Pages 2-4....
http://temp.corvetteforum.net/c4/scoob//c4heater02.jpg
http://temp.corvetteforum.net/c4/scoob//c4heater03.jpg
http://temp.corvetteforum.net/c4/scoob//c4heater04.jpg
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Dec 2006
Posts: 5,154
Likes: 2
From: Ft Myers Florida
I've done it like 3 times with new style and maybe twice with old. Without taking the ducting out. With the dash out (which takes like 10-15 minutes) you can get to the top one's without much fuss.
Ask Screen name 'Paul in Va' on ZR1 registry I replaced the core in his 91 ZR1 and he stopped by in hopes to see the dash all taken apart, but when he got there he was surprised to see I had it all buttoned back up by then.
I cheat by using a cordless drill to get all the easy to reach screws out.
Ask Screen name 'Paul in Va' on ZR1 registry I replaced the core in his 91 ZR1 and he stopped by in hopes to see the dash all taken apart, but when he got there he was surprised to see I had it all buttoned back up by then.
I cheat by using a cordless drill to get all the easy to reach screws out.
Last edited by Y-ME; Dec 20, 2011 at 12:23 AM.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
So, either this thread's advice is wrong -- for the OP's 91 -- or the magazine-printed-article is wrong.
(Note: The statement to which I refer is in column 2 paragraph 2 of the article I attached in post 13 above.)
Le Mans Master
Joined: Dec 2006
Posts: 5,154
Likes: 2
From: Ft Myers Florida
The OP has a 91 (vs our slightly older C4s). The OP is asking if the heater core is accessible via the engine compartment for his car! In the article I attached, it says (on page 1) that "In 1990, the General revised the dash and firewall so that the heater core comes out through the engine compartment".
So, either this thread's advice is wrong -- for the OP's 91 -- or the magazine-printed-article is wrong.
(Note: The statement to which I refer is in column 2 paragraph 2 of the article I attached in post 13 above.)
So, either this thread's advice is wrong -- for the OP's 91 -- or the magazine-printed-article is wrong.
(Note: The statement to which I refer is in column 2 paragraph 2 of the article I attached in post 13 above.)
Just kidding, This is on a stripped down ZR1 frame with everything removed, although the core fits through the hole, had the back of the heater box been intact I doubt you could get it through there also the core is strapped in and you have to take the core box cover off to get to the strap screws. Also I would think removing the HVAC blower cover would be hard as heck with the engine in the car.
Last edited by Y-ME; Dec 20, 2011 at 11:25 PM.
Pro
Joined: Aug 2001
Posts: 617
Likes: 14
From: Loudon, TN
I've done it like 3 times with new style and maybe twice with old. Without taking the ducting out. With the dash out (which takes like 10-15 minutes) you can get to the top one's without much fuss.
Ask Screen name 'Paul in Va' on ZR1 registry I replaced the core in his 91 ZR1 and he stopped by in hopes to see the dash all taken apart, but when he got there he was surprised to see I had it all buttoned back up by then.
I cheat by using a cordless drill to get all the easy to reach screws out.
Ask Screen name 'Paul in Va' on ZR1 registry I replaced the core in his 91 ZR1 and he stopped by in hopes to see the dash all taken apart, but when he got there he was surprised to see I had it all buttoned back up by then.
I cheat by using a cordless drill to get all the easy to reach screws out.
Le Mans Master
Joined: Dec 2006
Posts: 5,154
Likes: 2
From: Ft Myers Florida
I would have driven to VA and gladly been your hey-boy for tools and such just to see you do it. Having done it once I know where I could have cut corners and save time if I had to do it again, but my 64 year old butt doesn't move as quickly or as nimbly as it did when I was 20.
