I have one of these GM cars that uses the Dexcool coolant. Apparently, there's been class action lawsuits against GM for the use of this. Apparently, GM has kept the vast majority of GM car owners in the dark about this.

Here is a link with 160 pages of complaints by GM car owners, all saying the same things. google even has suggested keywords in regards to Dexcool causing major engine problems.

http://www.consumeraffairs.com/automotive/gm_dexcool.html

what pisses me off is, they won't come clean, the Dealers are apparently taught to pretend like they've never seen any such problems. If they would just admit the coolant is defective, and flush it out and put some old fashioned, green coolant in, problem solved, but apparently they've struck it rich fixing the expensive problems, that's the only reasoning I can come up with for why they don't just help you head the problem off.

they just REFILLED my Mom's car with the Dexcool, and now it's eating through the gaskets AGAIN it looks like.

They did fix it the first time at no charge, because it was under warranty, the Dexcool dissolved the gasket in under 30 thousand miles the first time.

anyways, there's going to be a HUGE WAVE of these kinds of cooling problems in GM cars coming in the near future.

Apparently the slight electric current that runs through your engine produces electrolysis in the dexcool and produces a kind of sludge, also any oxygen that gets into the system (from damages gaskets, seals) gunks it up til it ruins your water pump, radiator, heater core, thermostats, etc, etc)