So here's where I am ...

This is what 120,000 miles of 3000-4000 mile oil changes look like.
The valve cover was an adventure to get off, but I was working on unfamiliar territory. The underside sealing edge has a lot of evidence where and why it was leaking as does the surface of the head. They really should have changed the design of the sealing edge. It would have been so simple.


Getting this side back on obviously can be difficult, so the plan is to use some old iron techniques to accomplish this ( Unless someone has some to offer)


Meanwhile it's time to change the plugs. More reports to follow. Thanks everyone for your support

That looks pretty clean all things considered (I'm no engine specialist though!).

That's super clean (and I am an engine expert).

Just make sure to use a dab of RTV on both sides of the gasket at the right-angle corners, where the gasket "humps" over the timing cover. Those are the most likely spots to seal incompletely and leak after repair.

Thx, I have taken photos of the corner areas where they added RTV and will follow suit. I have a slight oil incursion on the #4 Plug tube and the seals do not look replaceable. Further, the seals I had ordered for this look too large by a factor of .5-1 mm. Would putting a smear of black RTV be advisable? New aftermarket covers?
thx

The skirts have to be snug, you shouldn't need RTV if they're the right ones. If you do need to use sealer, use a semi-hard RTV like Permatex Ultra Black. The regular stuff from the parts store is about 100% likely to lose adhesion and blow out.

I should have said #3 plug / Yes, albeit the original seals are almost brittle now and it would be advisable to replace them

Hello again,
Being that the spark plug seals are not replaceable, I'm faced with having to replace the Valve Covers. Is there a good aftermarket alternative or are the OEM covers the only viable route?
thx

Valve covers are one area where you can usually go China-cheap without worrying about it. There's an eBay cover on my '04 Altima (also non-replaceable skirt seals) that cost $38 with gasket and doesn't leak a molecule. Molded thermoplastic is something the aftermarket is good at.

thx, I'll look it up