Heater core saga again, now my 5th - Diesel Forum

Fordiesel69 · 11-19-2005, 11:07 PM

Well the first 3 were the autozone el cheap chinese ones made by Modine. The fourth one was a Valco/Motorcraft one I bought from Ford. All these cores only last 1 ~ 1.5 years. What is the problem?????????

I am using Fleet Charge coolant which is a very popular diesel coolant precharged with SCA's, and I measured the electricity in the coolant and it reads 0.049 ~ 0.087 DCv depending on the amount of throttle. Is this bad????

I decided to solder some copper wire to the new heater core tubes and run it to the - battery terminal, this way if electrolysis is the problem, maybe having a ground will help eliminate the erossion.

Anything I am missing????? Has anyone had frequent failures or it this just my luck?

BullHauler · 11-19-2005, 11:57 PM

About three years ago the original core in my 85 started leaving a couple drips on the floor mat. I replaced it with whatever Advance sells and no problems yet.

Are you using tap water or premix antifreeze??

In my neck-of-the-woods, well water or city water is so full of calcium that it corrodes everything; so I use pre-mix anti-freeze.

Greenie · 11-20-2005, 05:01 AM

Distilled water is available at most grocery stores - I have 12 years on the radiator and heater core w/o problems

DevoK12RS · 11-20-2005, 06:57 PM

I don't know if any of this will help you cuz it seems like you've covered your bases, but it came out of the installation guide/ owner's manual from the heater core that I just installed a couple of months ago.
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After removing the failed heater core from the vehicle, find out why it failed: is it the original heater core? Was it replaced before? If so, how long ago? If the heater core has been replaced within the last 6 months, you may be looking at a cooling system problem, not a heater core problem. What is the condition of the coolant: color? pH? any residue in the filler neck? The color should not be muddied or “rusty” in appearance. The pH should be in the range of 7.7-11.0. And the mix should be 50/50. Test the heater core for leaks: pin hole leaks in the core could be a sign of Electrolysis. This condition is usually a result of add on equipment- stereo amplifiers, alarm systems, plow lifts, etc.- that have not been properly grounded to the vehicle. You can test for this by using a DC voltmeter: submerge the positive lead into the radiator fill neck and ground the negative lead at the battery. This should be done with the radiator cap off and the engine running. You should not read any more than 0.1 volts. Any higher reading is cause for alarm and the offending component must be found and grounded properly. Stray excessive electrical current can destroy an aluminum heat exchanger in a very short time.
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Your volts are below the guideline they provided, but your upper reading is close. They say you can eat an HC in 6 months with VDC >.1. You're at .05 - .9. Maybe eat one in a year or so? Don't know...

I've wanted to check mine since then, but haven't gotten around to it yet. I think the HC I pulled was the original or the PO installed a OEM part.

HTH someone at some point.
Devo

Fordiesel69 · 11-20-2005, 07:26 PM

Well that is usually how I do things, find out why it failed. This time it has me stumpped. The coolant is only a year old and has maybe 3k on it.

The only thing I may have done is when I removed the heads, I may have painted the section of the drivers side head where the engine ground went, but wouldn't something else malfunction? I also soldered some wire to the heater core and ran it to a good ground. I then checked the resistence between the heater core and the - battery post and it measures infinate and the beeper buzzes on my meter. So I think if it was electrolysis, this should prevent it taking place.

Birken Vogt · 11-20-2005, 08:38 PM

Always the obvious first...check to make sure the heater hoses are long enough and the motor mounts in good condition so that when the engine torques around, it is not stretching the hoses. Also make sure no loose metal is rubbing a hole in the core.

Birken

Huff · 11-20-2005, 08:54 PM

I'm thinking along those lines as well.

Fordiesel69 · 11-20-2005, 09:38 PM

Good point, lines are plenty long as I have put those flush things in them, secondly I always had to wipe down the inside of the plenum and did not notice anything sticking out or even remotly close to rubbing the core. The new core comes with a new foam pad for the top as well.

BullHauler · 11-20-2005, 11:41 PM

What are "those flush things"??

soulpatchfr · 11-21-2005, 12:50 AM

i think he's just talking about a generic doodad that you'd install into a heater hose - cheap & readily available. there's a cap you can unscrew & it has garden hose threads... i've seen people use them to 'burp' the air out of the system, too.

cdnsarguy · 11-21-2005, 01:19 AM

What percentage of Fleet Charge and distilled water are you using...

From their web page........
How much Fleet Charge do I need for corrosion and liner protection?
Minimum 45%
Optimum 50%
Maximum 65%

I see several types of Fleet Charge.....

Fleet Charge, Fleet Charge 50/50, Fleet Charge PG... which are you using.

Fred Hemer · 11-21-2005, 01:22 AM

Take heed of this comment >Distilled water is available at most grocery stores< worth tring in my opinion!Unless your using premix!
Some tap water is terribly corrosive!Our comunity water is real hard on plumbing and yet perfectly fine to drink!

Fordiesel69 · 11-21-2005, 06:42 AM

Ok, yes those are the flush things I was talking about. I am using my own distilled water that I saved from my dehumidifier. I usually keep 10 gallons so it is probably a year old. The ratio is very close to 50/50 if not just a hair more concentrated from the top offs.

BuilderBob · 11-21-2005, 08:35 PM

[ QUOTE ]
I am using my own distilled water that I saved from my dehumidifier.

[/ QUOTE ]
There is the clue, no one has lost 5 heater cores, and no has used water from your dehumidifier.
I don't believe that the water from your dehumidifier can be called distilled.

cdnsarguy · 11-21-2005, 10:33 PM

On questioning the Ford master tech today he suggested a higher than normal water pressure in the heater core may be the problem. He stated they had this problem and were forced to restrict the pressure to the HC. How they attained this was by soldering a penny on the inlet of the HC with a smaller hole drilled in it. I think a ball valve would restrict flow and do the same thing by being half closed, should insufficient heat be allowed to the core at least you could open it a bit more.

I would not discount the humidifier water as a contributor though.