97 F-150 Heater Core 4 times replaced in 15k miles!

there are testing strips you can get that will tell you the PH of the coolant as well as the protection levels of it. to be honest, I'm thinking there may be a bad head gasket or intake manifold gasket that's allowing combustion gasses to contaminate the coolant. This can create an imbalance and allow for corrosion to occur. The Odd thing of your story is that the radiator is working fine, but the heater core keeps failing. I'd look at where the heater core is failing and see if it's in the joints.

Try this, install a 7 PSI cap and it reduces strain of heater core vs stock cap. I have used them for many years with a 60/40 coolant mix or better and never had any heating issues nor lost a heater core yet even in some very old vehicles (27 year old plus) For that fact, no leaky radiators either

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there is a tsb on that. run a wire from neg batt terminal post to metal on the radiator or heater core.

The core needs to be examined to see if the leak is due to corrosion or some other form of failure. It would make the solving the problem much easier. John

Correct! "TBS 01-15-6 Climate Control - Repeat Heater Core Failure" The "wiring harness" they put on may not be making good contact. Electrolysis is still the problem.

Congrats, you're an idiot.

A TSB having been published that long ago. lays the Dealer at fault. You might want to have a 'talk' with the Manager of the Service Dept! The conversation might include words like; 'lawyer' 'lawsuit' 'judge' 'court' 'bad publicity' 'newspaper'.....The way I see it is that you were defrauded because of the Dealers' incompetance. Raise hell!

Dave S(Texas)

The TSB ground wire was attached with core #3 and the new wiring harness. Also a lower pressure cap. Since Dad's death I have not put 2k miles on core #4. Obviously the dealer in question is incapible of getting it right, and since it's an all day labor job, they are tired of replacing it too. I have heard that using an aftermarket core instead of the Ford piece might be useful also. Thanks for all the input!

I have no idea what your problem is, but my expereince is that your FIRST heater core should just now be starting to go. Without knowing anything about you or where you live, but knowing how long stuff lasts around here, I see no problem getting upwards of 10 years out of a heater core.

Well if that ground wire was properly attached, then I suspect cooling system maintenance. My truck is an '81F100 that I bought new. The OEM core lasted 11yrs. I replaced it with a well know brand name core. It lasted 10yrs and was again replaced. The truck has 300K miles on it now and I'm looking at another 5-7 yrs to the next replacement time. I back-flush and replace coolant every two years....religiously. If the cooling system was properly maintained and the ground wire_is_properly attached, then the only thing left is.....water! Try using distilled water instead of 'hose' water. All these 50/50 premixed coolants use distilled water. I've never used the premixed type and don't intend to, but since distilled water is 'inactive', it's something you might consider using in your system. Hope this is of some use....

Dave S(Texas)

We're talking an average of 2-3 MONTHS per heater core! We're talking about a truck that's been PARKED for the last two months! I assume that new coolant was used for each install, and it certainly hasn't had time to contaminate.and I might point out that Dad's OEM core lasted 10 years also! I know the service manager had warned Dad about other instances of 5-6 heater cores being replaced in a short period of time (not by that dealer but apparently from Ford horror stories). They really wanted him to trade it. By the way, they also put a restrictor in the heater hose as per Ford tsb's. I just want to get the damn thing fixed long enough to sell it. I'm a hard core Dodge guy and this ain't helping my opinion of the F-word trunks! That 3 dollar can of stop leak is starting to look REAL good. :). Anyway again, I appreciate all the advice.