Hoping for some input from fellow impala owners. I had my 2005 impala (160,000 mi) in for suggested coolant flush because coolant was only reading good for 0 degrees F. Had that done Saturday morning at my local Chevy dealer in Green Bay - this morning on my way to work in 5 degree weather the temp gauge quickly pegged out to the max - pulled off the highway and let it cool down and and was able to limp home on the back streets. The dealership picked it up with a tow truck and looked into it - they called me and told me that it has a bad head gasket and loosing coolant thru the exhaust - $1700 to repair at Chevy garage. I had the head gaskets replaced on it at about 110,000 (50,000 miles ago) at a chevy dealer Upper Michigan a couple years back. how in the world to gaskets only last 50,000 miles? Is that dexcool that is required that terrible? Or just GM's designed obsolecence? Could there have been something during a coolant flush to cause this? Air trapped in the system maybe? I am going to call around local shops to get estimates - the car is barely worth the cost of repair.