Radiator Fan Hits Shroud

Any ideas? 93 S-10 Blazer, 4.3L W Motor, 4WD, Automatic. The radiator fan has started to hit the bottom of the shroud on startup. Just barely. By the time I get out of the subdivision (1/4 mile) it stops. Almost sounds like motor mounts, and how tough are those to change?

Put a couple of shims between the bolted 1/2's of the shrouds, they typically warp a little over the years, this will lower the bottom slightly.

The plastic does warp, or if you didn't put all the screws back in and only a few, it has a tendancy to shift and again probably warp. I had the same problem with my '95 and the plastic looked good all screws in there, in my case it was the engine mounts, they were getting old. Once the engine was started the heat would get to them and start expanding the rubber a little pushing the engineup, just enough to stop the noise. Also the colder it was, the worse the noise got, for obvious reasons.