Constantly replacing heater cores

[Edahall]

The 3rd heater core that I've installed over the last 2 years is now leaking again. Anyone else having this issue? Is there a better made heater core that I should buy?

[Jaysonb]

You should have test done to see if there are exhaust gases in your cooling system. I had a truck that ended up having a small head gasket leak, when I would step on it hard, it would make the heater core leak. Just somthing to check.

[Edahall]

Originally Posted by Jaysonb

You should have test done to see if there are exhaust gases in your cooling system. I had a truck that ended up having a small head gasket leak, when I would step on it hard, it would make the heater core leak. Just somthing to check.

Well, there is no chance for the cooling system to build pressure because I normally keep the radiator cap loose.

[lilpoindexter]

Cop car mustangs had a restrictor in the hose leading to the heater core to prevent this problem.

[tucsonjwt]

I have always used copper heater cores and have had no problem. I don't know about the aluminum ones. I don't know if an aluminum heater core and a copper/brass radiator are compatible. My guess is that the coolant that is supposed to be good for all types of engines should overcome that issue.

[TrailerTrash]

Originally Posted by Edahall

Well, there is no chance for the cooling system to build pressure because I normally keep the radiator cap loose.

say what?

[wesmigletz]

If you are running an aluminum heater core, I recommend using distilled water instead of water out of the tap. You can also replace the petcock on your radiator with a pipe plug that has a built in sacrificial anode... it will protect the aluminum components. My 62 Vette used to eat aluminum radiators and surge tanks. The sacrificial anode and distilled water fixed it.

[Bears63]

Wait, wait.... Why do you normally keep the radiator cap loose?

[Dead Parrot]

What brand(s)/source(s) of heater cores have you used?

They make radiator caps in lower PSI ratings if you don't want yours at 15 for some reason. I switched to a 7psi cap a few years back when I used some stop leak to get a bit more service out of my failing heater core. Much nicer to fix in spring vs middle of winter.

[CSHADES]

You need to check your coolant for electrical current. If you have some poor grounds the current will use the coolant to make a new ground which will damage the heater core. Using a volt meter put the ground lead on one of the heater core nipples and the other in the coolant at the radiator fill point and see if it shows any voltage. If it does you need to address some grounds.

[wesmigletz]

Good point about the grounds. Definitely worth checking.
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[Edahall]

Originally Posted by Bears63

Wait, wait.... Why do you normally keep the radiator cap loose?

To keep these heater cores from leaking all of the coolant into the passenger compartment. This heater core was just installed less than 6 months ago.

It was purchased from O'Reillys and it's an aluminum heater core with lifetime warranty. Right now, I'm getting coolant smell out of the heater vents and windows are steaming up so I don't have much time left before I have to replace this one.

[Edahall]

Originally Posted by CSHADES

You need to check your coolant for electrical current. If you have some poor grounds the current will use the coolant to make a new ground which will damage the heater core. Using a volt meter put the ground lead on one of the heater core nipples and the other in the coolant at the radiator fill point and see if it shows any voltage. If it does you need to address some grounds.

CSHADES,

I measured voltage between the heater core nipple and the radiator and got 0.22 volts.

[Edahall]

Is a 0.22 V differential enough to cause my problem and if so, what's the fix?

[CSHADES]

That isn't horrible but it is a bit more than you want to see. Also check the voltage from the ground on the battery to the coolant just to see what voltage you have there. I would clean all grounds, make sure you have good grounds from the engine to the body and good grounds from battery to the body. Also flush the cooling system and get fresh coolant in it. DO NOT put a ground on the heater core like Ford tried for a while that will just speed up the demise of your heater core. The lower you can get the voltage to the longer your parts are going to last especially aluminum parts. They can be sacrificial when it comes to electrolysis.

[tucsonjwt]

So, if your radiator is on its last legs, you can get a Spectra aluminum radiator for about $100 when you put in a new aluminum heater core. The new coolant is supposed to be good for any type of radiator (the yellow/green stuff.)

I used to be a copper/brass radiator and heater core fan but the ones you get now seem to have small leaks. When I changed the radiator in my 2002 Cavalier beater last year (also about $100) I discovered that it had the original aluminum/plastic radiator (14 years old) and it was not leaking - just clogged up with gunk and not cooling at highway speeds. So, I am now a plastic/aluminum fan. I have an aluminum radiator and copper heater core and so far no problems (but I don't drive the truck much.)