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I have the heads off of this LS5 and the car has a bad heater core. No AC car. It looks like there is a heater core cover bolted to the firewall/heater box. Can the heater core be replaced under the hood? If so, now is the time. TIA John
I have the heads off of this LS5 and the car has a bad heater core. No AC car. It looks like there is a heater core cover bolted to the firewall/heater box. Can the heater core be replaced under the hood? If so, now is the time. TIA John
On a non-A/C car the core comes out from the engine compartment side as you've correctly guessed.
On a A/C car the core comes out from the interior side.
Pretty simple job on a non-A/C car.
Might want to pressure test your replacement core before you install it.
You can do it simply using an old bicycle inner tube.
Cut the tube, attach the cut ends to the core using hose clamps, put some air pressure in the tube via the inner tube nipple, submerge the core in water and look for leaks.
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definitely replace it now. And you can repaint the box and clean up that part of the engine bay. IF you have a shop vac your going to want it handy to suck up all the crud you're going to find in there. Make sure the one you buy is a harrison or is a direct fit. I got a cheap replacement from autozone or rock auto and it was slightly smaller than th eoriginal
On a non-A/C car the core comes out from the engine compartment side as you've correctly guessed.
On a A/C car the core comes out from the interior side.
Pretty simple job on a non-A/C car.
Might want to pressure test your replacement core before you install it.
You can do it simply using an old bicycle inner tube.
Cut the tube, attach the cut ends to the core using hose clamps, put some air pressure in the tube via the inner tube nipple, submerge the core in water and look for leaks.
i replaced my non-AC heater core about a year ago with a cheapo aluminum one from amazon. It turned out to be a little bit longer than stock, but there is a metal flange inside the heater box that i just did a bit of cutting with some metal shears and bending to get the new one to fit. You could probably put some foam in there too to make it super snug, but I didn't feel the need. It's been working great and solved my steam on the windshield issue.
I really should have put new heater door seals in at the same time to reduce the amount of hot air into the cabin with the heater door closed. About a week later I put some valves on the heater core inlet and outlet lines to allow me to totally cut off coolant flow to heater core to eliminate this source of heat in the cabin. I heard folks even get a bit a bit of heat after replacing the seals.
If you're a real stickler for originality, it makes sense to get the copper one, but who would know?
Well I finally got the new core in. Removing the old one from the box and installing the new one is a tight fit (PITA). I damaged the old retainer and could not locate the correct replacement. I did find 64-81 GM retainers at inline tube that worked fine with my core.
1971 Heater core replacement.
