my '79 450SL is making a noise that is best described as "wind howl" from under the hood, it appears. It's like you hear when you are in an enclosed room and you can hear the howl of the wind outside. Now, the interesting thing is this noise is present until around 3100 RPMS at which time it subsides. We even ran the car in second gear and the pattern repeats. It sounds as if it is from the engine compartment.
We recently rebuild the transmission, replaced the cruise control controller, removed an aftermarket security system.
Any guesses on what it is? As soon as I hear back from my tech I'll post the "answer". The winner gets a one year free subscription to MercedesShop.com