1998 GMC Jimmy Anti-freeze rust

There is a pending lawsuit on this issue where the antifreeze reacts to the metal of the engine/radiator and turns everthing to rust. I had to deal with that issue at the beginning of this year when I experience the loss of heat in the vehicle. My mechanic is the local gas station mechanic that I have used for 20 yrs, he first replaced the thermostat, was fine for about a month, then went cold,he then tried flushing the heater core several times only for it to work for awhile and get clogged up again with this rust filled anti-freeze, he eventually adv me to replace the core…but didnt have time to do this job, I then took the vehicle to a specialized Radiator/Air conditioner shop that I have used in the past on a different vehicle. That mechanic adv me that he has dealt with that (rust) kind of trouble before and recommended having the radiator soaked/cleaned first and not replace the core, which he did, then only to discovered I had to have the head gaskets replaced as well, ok that total repair set me back $1300, I had nice strong heat for approx 1 mth when it went cold again, took it back to the specialty shop, he flushed the heater core, although the anti-freeze fluid looked fine, he tried changing the thermostat but no change… the heat was fine for 2 weeks then went cold, he flushed it again, was fine for 2 weeks then this time it just went lukewarm. Since we are now in summer I have not had to deal with that issue as heat is not required, but am concerned that when fall hits I will have to. Am I looking at having this core replaced anyway?..

This sounds like a typical DEX-COOL horror story. Some years ago, my mechanic replaced the rad on our Nissan and put in long life GM antifreeze (DEX-COOL), since he is licencsed by GM to upgrade the performance of truck engines for traler towing.

The rad failed after 1 year, just the time I read about the GM issue. My mechanic gave me a generous adjustment on a new rad and put in free regular Prestone universal antifreeze. My mechanic has sworn off DEX-COOL.

You may have to replace your rad again, and keep all your records, since you should be entitled to a settlement.

Good Luck

This is a 10-year-old vehicle so the first question is: How many times had the coolant been replaced before the rust problem first surfaced? The rust inhibitors in standard antifreeze last only a couple of years. If your original antifreeze was 6 or more years old when you first discovered the rust problem, then you can’t really blame the coolant unless it was labeled as ‘long life’ coolant.

That being said, I was one of many victims of Dex-Cool. My problem was that it attacked plastic parts in my cooling system, destroying an new aluminum/plastic radiator in only two years as well as several other parts that I am still replacing. Virtually every part of my cooling system that had an O-ring in it, from the radiator cap down, that was in the car when I ran Dex-Cool, has required replacement. GRRRRR. My head gasket is still OK (I hope).