I'm trying to think of a way to describe this to you. The only thing I can come up with is that if it is so wet with oil that it soaks the air filter, you have a problem. If not, you can probably just keep it wiped down as long as it doesn't use lots of oil.
100K miles is generally considered low mileage on these engines, however, it depends largely on how it has been driven and maintained. It would be possible for one of these engines to be completely worn out at this mileage if the oil has not been frequently changed, the car was driven on short hops and/or it was driven very hard.