New noise

[Tuff_Shift]

Recently, after the C3 has been sitting for a week or two, when starting it up, there is a rat-tat-tat-tat-tat noise coming from the fan blade lightly striking top of the fan shroud. Once I put the car in gear and drive a few blocks down the street, the noise stops. For the life of me, I cannot figure out WHY that is happening, and what I need to do to prevent it from happening, or getting worse. Any ideas would be appreciated. It is a 1979 coupe, all stock automatic.

 

[Tom Bryant]

Welcome to the CAC.
I can think of a few reasons why it would happen but few why it would stop. If it has a clutch fan, it could be loose and wobble if worn and then tighten and stabilize when it warms up. and starts to engage. I would also check shroud mounting bolts to be sure none were loose, or any tabs broken off. Then look at the motor mounts.

Tom