I've had the heater core replaced twice since I bought my '97 F-150 7 years ago. It's going again, filling the cab with steam and leaking onto the floor. A mechanic said they might be going out because of an electrical short that's changing the electrolysis of the coolant.( I heard this is what causes Subaru's to blow head gaskets) Anyone hear of this before? What are other possible causes for the core to keep crapping out? thanks.

 

Couple of good ideas in this thread

http://answers.yahoo.com/question/in...7180059AAQu8oW

One of the posters mentions electrolysis and that there was a TSB on the issue. Could be a bad ground.

What motor is in your '97? That year's 4.2 V6 was known to have some issues with gaskets, and I suppose that could be causing your cooling system and heater core to be pressurized.

 

My 97 had over 300,xxx miles on it and i never replaced the coolant and never had any problems....

 

The mechanic is correct and it's a common thing. Hopefully you've never used anything as an additive to the coolant like water wetter. If so, sell the truck as you can't flush it out even with acid. You can also have a bad ground strap from the engine to the frame of the truck causing the issue. DO NOT put a ground strap from the radiator to the battery unless you like replacing radiators.

 

dang! nice!