So tonight it was raining rather hard a little. My truck was cold (01 Silverado 5.3) I let it warm up a little then started driving less than 25mph in my neighborhood. It started to feel a little sludges and I put the peddle all the way down and it cleared up and felt fine. 20 seconds later, it was doing that again, so I put it in park and reved it out twice and called it quits and started going back home, on the way back my Check engine light came on flashing (miss firing) and I put it in first to keep the rpms up just in case of water I could burn it out. I parked my truck and reved it 5-6 times all the way and they idled it and shut it off. I started it 20 min later ran fine, check oil and it was good. Should I do anything like pull a plug or anything? I have a k&n 57 series cold air, and never had this issue before but I'm going to get a cover for it now, but anything I should do to be "Safe"? Help

 

Sounds like my camaro when it rains heavy. For me my cowl seal leaks and it gets some of the coils wet. I'd wait until it dries and see if it clears up.

This happened to me today actually, like 8 hrs ago I just reinstalled my tb that I ported and fired it up
it started down pouring. A few mins after it started raining it got the wobbly idle. I drove it around a little as I knew why it was missing, it drives fine on top end, but it'll miss down low. Fast forward 4-5 hours and I had to go out for some things. Started up. Idled fine, no more miss.

 

Definitely not hydro locked. The camaro I hydro locked had a hole in the block the size of a softball and left a huge oil trail on my brand new concrete driveway. It made a huge cracking noise when it did it.

Water is not compressible. If it even turns over it isn't hydro locked.

 

Yea, no hydro lock. It wouldn't turn over if it was. It would have bent a rod most likely if it was. Sounds like you had moisture as mentioned above. Maybe causing a misfire at a coil or wire.