On the passenger side valve cover, there's a hole about halfway back. It's got a rubber grommet with "threads" molded into it. What goes in there on your engine? I had mine into the dealer a few weeks ago for a spark plug change, and didn't notice it until today. There's nothing hanging loose around there, so I have no idea what goes there.

All I need is one person to go out and look at theirs and tell me what it could be.

Thanks a bunch!

 

I've got a 2002 SD Crew Cab 5.4L - The hole I'm assuming is about 6" behind the Oil Filler. There is something in it that connects to a hose that runs to the back of the engine. The last engine I every worked on was an Olds 442 back in the 70's, so I really don't have a clue, but it looks like an emissions sensor of some sort. Sorry I can't tell you exactly what it is. George K

 

GeorgeK-NJ: Thank you!

You are correct in it being about 6 inches behind the oil fill. I'll have to look around the back of the motor and see if there's something hanging around that was disturbed when they changed the plugs.

Thanks again!!!

 

I looked for a PCV valve, and sure enough, pushed out of the way, there it was.

Thanks for the help!