I need advice. I wasnt aware of the Dexcool issue until last year. And I converted my 82 Suburban , 86 VW, 82 Goldwing to Dexcool over three years ago. To make it easier to deal with all the antifreze types I had. If i get it out of the suburban, and VW Ive got three types to deal with now. As stupid as this sounds . My Toyota has its own. The VW does too,no silicates, And the Goldwing too, But susposedly , Dexcool has been working in Goldwings with no issues. Should I change it back or is it too late. My understanding is GM put stop leak clay in the Dexcool to get it through warrranty without leaks. And it wiped out everyones engines and heater cores and headgaskets. I copied this from a forum.
Although my information is a little dated, we Impala SS owners have had incredible problems with DexCool. About five years ago I asked about 500 Impala SS owners to relay their exact issues and I compiled the info.
Basically, here is the issue as we see it. First of all, you have to understand what goes on at GM when a vehicle is designed/planned in Detroit. The different departments are set to their tasks. Weekly they meet and discuss and constant communication is maintained either casually (over a few beers after work) or formally (memos, phone calls, etc). In the end 90% of the vehicle's build properties are determined by about 30% of the team. The rest is left to the interns, staff flunkies, and other smaller teams.
With that background... In the case of DexCool, two main problems happened.
1) GM didn't properly read the information that its designer included with they coolant they designed. GM over-rated its life by a considerable amount. It spawned a lawsuit since GM's misrepresentation cost the designer (which I think was havoline) millions. 2) In light of the above paragraph, the 30% of the team making decisions about the cars didn't listen to the 70% interns and flunkies when they recommended against the clay tablets in the coolant. GM made it a policy to include clay tablets in every car's cooling system. The idea was that the inexpensive clay tablets and their dissolved silicates help to plug leaks. They are highly ineffective, but if it masks a leak for 5 extra miles which takes the car out of warranty, it has paid for itself a million times over. The clay tablets that GM used for decades didn't mix well with the DexCool. It causes silicates to precipiate out of suspension and you basically have sandy water in your cooling system. We SS owners for several years called it "orange jello" since thats what it very closely resembled.As of 1998, GM had done nothing. They continued to put clay tablets in with DexCool despite millions of consumers, flunkies, interns, and Mr. Goodwrenches screaming at GM. It was such big business and Dexcool was such a small thing that it was about as important as a hangnail is to a boxer. Everyone was screaming, "dexcool, dexcool!" but all GM execs heard was "blah blah, blah blah!" Classic case of the left hand not knowing what the right hand was doing.
Since 1998, I'm not sure what they've done, but there are TSBs at these websites....
Generally you just need to shine a flashlight down into your radiator every month or so. If the coolant looks decent and the level is staying up, you have no problem. If it is murky or, heaven forbid, muddy looking, you have the beginnings of a major problem. If you're losing coolant the Dexcool or the engine design has your intake manifold gaskets leaking. The jury is out on which causes this I think. The Dexcool is primarily designed to keep owners out from under the hood until the warranty is up, then when problems develop, its your nickel. My suggestion is to get the Dexcool out, replace with the new long life Prestone that's available about everywhere