Ok, heres the background. I'm on my 6th heater core in a little over a year. Replaced my radiator 7 months ago and now it is leaking... again. The problem I'm having is called electrolysis... coolant system has a electric charge in it and turnes the the antifreeze to acid and eats out the heatercores. The dealership told me there was NO WAY that the problem could ever effect my radiator or anything else having to do with the cooling system. I find that hard to believe since my 2nd radiator failed after only 7 months. So my question would be how do I fix the problem of electrolysis? It has been diagnoised but nobody has been able to offer a suggestion as to how to fix or find the problem. Is the truck just a loss cause at this point? Also, is there anything stopping the electrolysis from eating any other part of the cooling system? As far as I can tell if it can eat a aluminum heater core then it can eat anything else aluminum. Thanks for your help, this is a problem that I have been fighting for over a year and I am just at a loss at this point.

 

Make sure all of your ground wires that go from the engine to the body and frame are good. Not to sure how electrolysis is turning the coolant to acid though. It sounds more like your coolant has a high conductivity which promotes electrolysis. Electrolysis is the transfer of electrons between dissimilar metals I dont think it can change the PH of your coolant. Something else to try is give the entire coolant system a good flush and refill with 50/50 antifreeze and de-ionized water that will lower the conductivity.

 

Do a search in Engines or HVAC for electrolysis. I remember this coming up a few times back in the winter and the solution might have been a ground strap to the heatercore.

 

There was a post somewhere that describes running another ground from the rad to the body.You can check for voltage by multimeter.Dip a probe into the overflow and the other to the body set the meter on milli-volt and ground the rad until it's gone.Also check the rad housing to the body in milli-volt and ohms if you get nothing at the overfill.Check it while running and shut down.Don't know the exact event horizon but the closer to 0 milli-volt or 0 ohms the better.Be sure to check it this way or it may still be there.Ypu have a 98 and they are known for it.Over time a pin hole can appear next to the thermostat.Thanks for the reminder i will check mine when it gets back from the shop with my new gears.
cheers

 

See TSB 06-21-19 for the updated checks on how to test for the presence of electrolysis.

Do NOT ground the heater core. See the TSB for details why.

Steve

 

Yeah some of the posts about the problem in the HVAC forum were most likely from me about a year ago when the problem first arose. The system has been flushed and the fluid changed multiple times (every time the heatercores and radiator were replaced). The dealer checked the voltage level last time the heatercore was replaced and it was holding a 6volt charge. All grounds have been changed by the dealer as well as more added. Still this problem exists!!!! The heatercore is currently grounded (both inlet and outlet, done by the dealer). I'm just sick and tired of seeing green puddles under the truck every couple of months!!!!