Replacement heater core

Merle Nelson

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Dec 29, 2012
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Let my mechanic put an aluminum replacement heater core in instead of copper/brass. He said there would be less electrolysis issues.

There is also a lot less heat put out. I would say by 40%. Don't do it.
 
Yeah al is supposed to transfer heat very well, fin tube for baseboard radiators is copper pipe with al fins. So I second what Jim said. I would suspect there to be electrolysis issues too tho, but it would be the heater core that would be reduced, so you are in the same boat as before.
 
It's not so hard to diagnose a heater core.

Sure, if it's leaking it needs replaced. If you don't have hot air it's time to look at other problems.

No airflow through the core but no temp diff indicates the outside is plugged.

Too great a temp differential indicates a plugged core.

A proper temp diff but no hot air is most likely a blend door problem.
 
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  • #8
F350 old heater worked great, just started smelling a sweet smell in cab when heater on and fogging window. Now the heat output is nowhere near as hot.

I saw that he just clamped end of heater core hoses in engine compartment, replaced heater core, cut to fresh ends on hoses and re-installed. I wouldn't think there would be any issue there.
 
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  • #12
Mine is a 1990 F350 with a 460. Jim.....you don't get to brag, 'you got older stuff' with me. :) (Though I'm sure you can trump me with something in the back 40 rusting down to its frame rails.)

I'll check the blend door just for fun. But, I figured, hot before aluminum installed, not nearly as hot after, pointed to the functioning of the metal/core itself.
 
As someone who's twisted a lot of wrenches myself, you really need to listen to Jim on this he is giving you proper helpful advice.

Lots and lots of aluminum heater cores out there providing plenty of heat. 40% or so (very noticeable to you at the least) heat output reduction points to something other than just the difference between aluminum and brass/copper.
 
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  • #15
"Never Mind" as Gilda Radner used to say. :)

I think there was just a bunch of air trapped in the heater core because he didn't drain and refill the coolant in the system. After a few more mornings of use and one of those being a short drive with the cap loosened it started to heat better and better. It's at normal now.

Thanks for the help, I would have gone onto some of the clever diagnosis ideas if I would have needed to.
 
Ah yes, the all powerful airlock... Have spent wayyyyyyyyyy too much of my life being fooled by them (I am a pipefitter after all)
 
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