I was fed up with leaks from the PVC covers on my SRT6 valve covers.
I decided on an aircraft fuel tank sealant that is formulated to handle relatively high temperatures in the prescence of gasoline.
I bought the sealant on line from AVIALL, a Boeing Company.
I purchased the small kit, 0.5 fl oz, with catalyst. This is more than enough sealant to service both PVC covers, however the working time is only 30 minutes. Down here in Florida it was more like 15 minutes. Buy two kits. Only around $7.69 each.
Now let me warn you, this stuff is tenacious, very similar to the marine caulk used to permanently attach boat decks to hulls. I bought glue syringes at ACE Hardware, quickly mixed a batch and laid down a bead in the groove of the cover as well as smearing a little on the raised tongue on the valve cover.
Now it's time for pizza and beer. I'll let you know if I see any leaks.

 

I admire your gritty spirit. Please let us know of your success or not.

 

Please let us know how it works out. I need to fix mine soon...
Wife keeps complaining of smelling something burning whenever she is in the car.

 

so you permanently glued your upper access panels on, while still on the car?

 

Road testing the new sealant has been successful! Sealant cured up in 3 hours, fully cures in 5 hours, but I didn't need the car until the next day. The bond has left a nice tough grey colored bead all around the pcv cover. I would say as long as it does not leak it will be "permanent", however, the bead that I laid down in the cover grove just filled it, so I think I could still pry the cover off with a plastic interior tool if I had to. I sealed the little glands around the screw holes but dod not seal the screws, so removing the engine valve cover as a unit should be no problem.
If you do this remember to do good prep on the tongue and groove interface. Very important, as the old silicone sealant can be difficult. I did a final brush down of the interface with a brass wire brush. Used acetone as a final cleanup prior to bonding. I also used a can of duster to blow out the little drain holes in the bottom of the vapor box as well as the scavenging hole in the cover. They were clean, but I was trained as an aircraft airframe and powerplant mechanic and I'm an aerospace engineer, so there it is then.
Good luck!

 

Yes, I sealed the pcv cover while still on the car. Only did the passenger side so far. Still waiting for the drivers side to start leaking after getting the last warranty repair at the dealer. One edge is getting wet with hot oil where the silicone sealant is breaking down, so it won't be long. The aircraft fuel tank sealant has a 9 month shelf life at room temperature, so I have plenty of time to work the job into my schedule.

 

Is this sealant "oxygen sensor safe"?
Don't mean to rain on the parade as it seems like you were methodical and meticulous in your use and application of the sealant, but I do worry about the oxygen sensors getting contaminated by the outgassing from the sealant (in the case where it is drawn back into the combustion process by the PCV). Curiously, i just did a quick internet search and find that most "oxygen sensor safe sealant" searches lead to dead links (bosch for example) and/or home-made lists of what not to do .... SO perhaps this (buying only "sensor safe" sealants) is much ado about nothing. Please let us know how it goes relative to sensor life, etc.

nice write up BTW

Cheers,
Chris

 

Oxygen sensor safe? The sealant self cures, so there is some outgasing. It gives off a sulfurous odor. Gasoline has plenty of sulfur as well. Then of course when you start your engine the vapors that are left are combusted in the cylinders before reaching the oxygen sensors. The catalyst is manganese dioxide. It does not appear to be given off as fumes, according to the MSDS. Read the MSDS and come to your own conclusions.
When the sealant is fully cured and has been heated to engine operating temperatures I expect the outgasing will be complete.