I'll let you guys know when they get this problem diagnosed but it seems to me that it should be more bullet proof then it is if you are correct. I mean to have such a part as that to fail and potentially ruin an engine of that calliber. I know it's NEVER good when oil and water mix. This thing that happened pushed out about 4 quarts of engine oil out the radiator overflow and onto my driveway.When I take off the cap , it's just grey with oil. Accually it looks more like oil than radiator fluid. I really hope its simple as a busted pipe.I must emphasize, I can't believe the two systems are that closely related.