I have a '94 318is with 120K miles. The car has been running great, but I live in Los Angeles, and overnight the temp has dropped to about 50 Farenheit. The weather has also been kind of wet/humid. When I start up in thge morning the idle is uneven, the fan by the radiator makes more noise than usual. As soon as I drive a few minutes these sympoms disappear and do not return until the next morning. Is there anything I should have checked? I know the car needs a bit of a warm-up but it really doesn't sound great when I start up in the morning--but it is weird that after a warm-up it sounds fine.