My 1988 GT heater core started to leak in 2023 and I read the comments under “Heater Core Question” which this thread started in year 2013.
Since I didn’t want an aluminum core, I searched for a copper-brass design and finally brought a #98498 ‘Four Seasons’ brand heater core.
This core has the CORRECT SIZE of 2.0-inches deep like the original Harrisons heater and manufactured in Mexico.
The core was made by Thermal Solutions Manufacturing, Inc (TSM in Nashville, TN) and the sticker says model 0398203 (FYI - This ‘model’ is the same number of the old Vista-Pro / Ready-Aire cores which were made of aluminum in 2013)
On the shipping label had ‘Four Seasons’ 98498 but also has 94498 (SPI) and 9010186 (APDI) Automotive Parts Distribution International
FYI: Drain, Flush and Refill your coolant at 30,000 mile or 2 years; my original Harrisons heater core nearly lasted 35 years!
And THANK-YOU member ‘RWDPLZ’ for the awesome ‘Fiero Heater Core Replacement’ write-up! My 'AC Equipped Fiero Heater Core Replacement' report from year 2011 was VERY helpful....
And THANK-YOU member ‘RWDPLZ’ for the awesome ‘Fiero Heater Core Replacement’ write-up! My 'AC Equipped Fiero Heater Core Replacement' report from year 2011 was VERY helpful....
Yes, great thread... and that first image was an awesome shot of my lawn and old heater cores, right?
CLICK FOR FULL SIZE
quote
Originally posted by Vintage-Nut:
This core has the CORRECT SIZE of 2.0-inches deep like the original Harrisons heater...
The biggest complaint with the aluminum heater cores wasn't their depth so much as their length. Not that it made any noticeable heating difference whatsoever, but there would be a slight gap at the end of the aluminum heater cores when installed.
I tried two of the aluminum cores, they didn't heat nearly as well. Found a new old stock brass/copper one by accident, installed that, and it worked just like the original.
The heater core is pretty simple to install in these cars, I also replaced what might be the most difficult one a few years later in a 1998 Lincoln Navigator, a 10 hour book job.
Originally posted by RWDPLZ: ... I also replaced what might be the most difficult one a few years later in a 1998 Lincoln Navigator, a 10 hour book job.
Ever do a 2nd gen S10/Sonoma? You have to remove the dash, which requires dropping the column. You have to remove the top housing(?) from the HVAC box. (I don't remember evacuating the A/C, so that must not have been a thing.) To remove the HVAC housing, however, you have to remove the right front wheel well. THEN you can get to the nuts that hold it.
Not sure of "book hours", but it took me all weekend.
Ever do a 2nd gen S10/Sonoma? You have to remove the dash, which requires dropping the column. You have to remove the top housing(?) from the HVAC box. (I don't remember evacuating the A/C, so that must not have been a thing.) To remove the HVAC housing, however, you have to remove the right front wheel well. THEN you can get to the nuts that hold it.
Not sure of "book hours", but it took me all weekend.
Not that job, but I did a ton of repairs to a 96 Blazer S10, including the #3 spark plug, which Snap-On makes a special tool for. That I wish I had at the time. That truck had 25,000 miles on it when we inherited it, but everything broke all the time, it was a complete lemon, made the Fiero look like a Toyota Corolla. When the brake lines rusted out, I politely declined to do the job, it's been rusting into the ground for ~8 years or so now with 40,000 miles on it, waiting to be hauled off to the scrap yard. It was the 2WD model so it was completely worthless in the snow, it got stuck on level ground a few times.
The heater cores listed for the AC equipped cars gives dimensions of 6 1/4 high by 6 1/4 wide. They are minimally 6 inches wide. My photo comparison shows the original Harrison core and a new 98498 Four Seasons core. http://www.gafiero.org/bbs/...27.msg37566#msg37566
Thanks for the warning on the Navigator - I have a '99 with about 150K, just thinking about starting to leak on me - had kinda assumed it would be an easy job. Up to now, the Jaguar XJS has ruled - bare firewall by the time you get the heater unit out of it.
Ever do a 2nd gen S10/Sonoma? You have to remove the dash, which requires dropping the column. You have to remove the top housing(?) from the HVAC box. (I don't remember evacuating the A/C, so that must not have been a thing.) To remove the HVAC housing, however, you have to remove the right front wheel well. THEN you can get to the nuts that hold it.
Not sure of "book hours", but it took me all weekend.
One of my Expeditions also had a leaking heater core and I needed a very similar process to replace it. In terms of replacement, this was not a good design even though it must have saved the manufacturer a few pennies per vehicle.
