O.K., so how do I remedy this? Drain system, flush w/water or flush product? Thanks for the info, do not want to ruin this truck! I also was reading somewhere that dexcool might eat my head gasket? By the way, I've got the dexcool approved Prestone coolant, it's not actual GM dexcool, don't know if thats better or worse.
1. Don't know about eating of head gaskets as a specific Dexcool problem, can't imagine why it would destroy only head gasket maeterial. After all, there are much more easily corroded parts like rubber hoses, et., al., that are not affected by Dexcool.
2. I believe that Dexcool is Dexcool is Dexcool, no matter who makes it. Mine was purchased from NAPA.
3. "...how do I remedy this?" Don't panic and try flushing it out before you know what's what. Regular citrus based radiator flush (like you get at NAPA) WILL NOT clean out Dexcool sufficiently to change back to the green stuff. There is a procedure that supposedly removes all traces of Dexcool from cooling systems but it is a long, drawn out, whole day process, using nasty chemicals and neutralizers, where you must keep cooling sys at certain temp for specific time, purg all air pockets, then re-flush again and replace ALL hoses, caps, thermostats, WITH BRAND NEW parts.
This is the official, recommended, GM dealer procedure which I did--- it was a PITA, and even after successfully completing this procedure and changing back to green stuff, my trucks cooling sys is beginning to gum-up again but nowhere near as bad. Looks like I'll need to do another flush and maybe try another chemical agent.
Some guys have reccomended using powdered dishwasher soap. like you use in the machine, and run it for several days, then flush and refill. Has anybody else tried this? If so, what ratio/mixture would I use?
Don't get overly worried here. Read this
LINK over a few more times. It gives specific things that can be done to maintain Dexcool in your vehicle with minimal problems. Follow that carefully--- something I didn't do--- and you may have no Dexcool issues at all. Not guaranteeing anything, but in fact some guys swear by the stuff and they use it in 1990's model vehicles without any problems. Recommend you keep your eyes on the overflow bottle and it's contents. If that starts looking cloudy and funny colored, that will give an early clue before the problem gets bad, like it did for me.
If worse comes to worse, you will just have to flush and re-flush your cooling sys a few times--- like I'm having to do.