So the first time I had to replace that cap was when I was putting my engine together. The FSM wasn't very clear on the seal packing, so I just put it literally where the pictures said to put it, on the edges of the cap, one dab on each side. Wrong. I had to take it apart and redo it. I cleaned the surface, getting rid of all the silicone I could, plus any oil, then covering the surface with black sealant. Same with the cap. Scraped (lightly) and covered (not drowned) in black sealant. Now, its leaking again. What the **** did I do wrong?

 

Are you letting it cure for 24hrs before cranking? Cleaning surface with acetone?

 

I just cleaned mine with some Spray 9, applied and let it sit with the valve cover finger tight for 1 hour, then torqued to the proper specs and let sit for 24hr. Next day no more leaks.

 

Number 6 cam cap should not need any more FIPG than what the illustration shows in the FSM. Too much can be make things worse. After installing the cam cap and before installing the vale covers did you run the small beads of FIPG along the 2 areas of the cam caps(per FSM) before installing the valve covers? How about the cam plugs, did you use any FIPG on those as they should not require any.

Also be really careful with those 2 bolt holes for that cam cap as they strip out very easily because of the length of the bolts. They actually engage very little of the threads in the head.Same goes for cap numer 1 on the passenger side.