Many people have had this problem, I have seen it on my rig too. Last winter it was a pain in the ass trying to drive 2 hours to go skiing in a blizzard. You can take this truck through some nasty terrain but it can't handle some cold temps and snow on the wipers that is BS. I can't believe that GM hasn't done anything about this. They replaced the jack and rear washer fluid pump for christ's sake; and the pump still blows chunks.
