I stole this photo from another forum.



The piece of stamped steal w/ the X looks like it may be leaking oil (bottom right side of the mentioned piece). The pass. side valve cover gasket has been recently changed.

From underneath, you can see it leaking near this location. Also on the ground I'm finding oil, not coolant which seems to be common.

Question, is this probable that oil is leaking from this location???

 

I was just in that area doing a HG on a 5vz-fe which the pic appears to be. Yes, it's possible that oil could leak out of that area if oil is able to leak past the HG and fill the well on the other side of the plate with an X with oil. Is your oil level dropping faster than normal?

Is the leak worse when the nose of the truck is uphill? Stopped when the nose is parked downhill? If yes, to both that area behind the plate (plate is part of the coolant water bypass tube) could be the culprit.

Re-check the VCG bolts to be sure they have remained torqued especially if you re-used the metal/rubber washers on each bolt. You did put a bit of RTV on the inside corners of the rear plug and on the 1/2 moon too?

Re-inspect the VCG area with a telescoping mirror paying close attention to the black rear plug on the VC, the VC to head interface, and the head to block interface.

The are some threads on other forums that have pics of that area with the intake plenum off. Do a Google search for 5vz-fe head gasket and the threads will pop up. Good luck.