I have a 99 Silverado 5.3L and have noticed that there is water in the airbox. I have not done any off-roading and it's not much, enough to fill 3 or 4 of the squares in the bottom of the box, but it concerns me a little. I have a K&N drop-in filter and I also noticed water droplets on the MAF side of the airfilter seal and the filter itself looks light pink like it has absorbed water. Just doesn't seem normal to me. I put the K&N filter in about 4 months ago and noticed the same thing twice now. Not sure if it's coming in from where it meets up to the fenderwell while driving in the rain or while its parked in the rain. My biggest question is, " Is it going to kill my engine or some other component?" or "Is it normal and I'm just over sensitive about my truck?"LOL!!