I have a second gen and the coolant gets "crap" in it. At first I thought it was oil, but now I am certain it is the radiator /trans cooler combo failing. As the weather warms I plan on adding an aftermarket trans cooler and plugging the factory lines. I really haven't taken a good look yet, but this is a well documented problem on opel forums, here and some of the 1.8ers. A recall would cost too much, but they should at least offer an "upgrade" factory alternative before we have to play Mcgyver. The Ecotecs have coolant gremlins and chevy has just ignored them, these engines debuted in 2002 ( I think ) and have not been fixed. Gone r the days of the 350 running for months while missing a quart of oil and low on coolant