Thanks for the reply and photo!
I have tried tightening the bolts but they are all already at or tighter than the stock torque so I haven't tried going beyond that. None of them were able to be tightened by hand as many have reported on here. Also, my driver's side VC is cracked around the front-most bolt and has been JB welded, I suspect that is a source of most of the leak.
As to the oil, I don't know what is in it now (haven't changed the oil since buying it) but are some oils better than others to slow a leak like this? I've always used Mobil 1 Full Synthetic in my vehicles but if a different oil may slow this leak I'd be open to switching.
You are probably right about the JB weld crack being the culprit, if you can't get the valve cover off a junkyard truck in you area I *may* be able to find one for you locally, I'd sell it to you at my cost plus shipping. Be sure to not over tighten the bolts as more JB weld crack mishaps may occur. I know this as I did it to a Chevy Blazer in my greener days, what really sucked is that it wasn't even my truck!
If I had to guess I'd say the guy you bought it from knew of the leak and tried to tighten the bolts and clean it up to hide it.
Good quality dino oil (Non-synthetic, so not the Mobil 1 you like to use) will definitely keep the leak slower than switching to synthetic. When I put the synth in it practically poured out. Ultimately there is no magical pour in leak stop. Least wise, one that won't gunk your engine up. Sounds like a afternoon of wrenching is in your future. In the mean time keeping a good eye on the level and topping it off with the correct weight non synthetic oil like just Mobil, will suffice. (Not Mobil-1, that's the synth stuff) What ever is on your oil cap assuming it is still factory and legible will suffice.
Between this tutorial and the one below it I got the job done, not the easiest but definitely not the most difficult either. I took my time and spent a lot of time cleaning up parts as I got to them, as well as just generally looking at how things worked and it took me about 10hrs. I'm sure it can be done in half that. I would definitely recommend Toyota genuine parts as well, to included the FIPG.
http://www.toyota-4runner.org/3rd-g...e-cover-gasket-replacement-part-s-n-pics.html
5vzfe leaky valve covers fixed (56k beware) - YotaTech Forums
Found and skimmed over this one when looking for that second link, it also looks good and includes a few extra things I did as well (Like the D to O gasket mod)
Valve Cover Gasket Replacement - Toyota Nation Forum : Toyota Car and Truck Forums
Lastly here's what all I did while in there:
Oil change to Amsoil 5w-30 Signature series fully Synthetic
Purlator Pure 1 pl20195 (The longer V8 filter)
Air Filter
Spark Plugs NGK Double Prong (Yep the truck calls for a two prong plug)
New NGK Wires
Thoroughly cleaned the throttle body, MAF and intake manifold
PCV Valve and grommet
Half Moons
Cam seals
Intake gaskets
New battery terminals
D to O gasket (Used a new metal one VS the Paper TRD one)
Air Fliter K&N Most people here hate these, some swear by them, I've always used one and just been light on the oil, I like it but OEM is just as good. I chose this one as I like to drive dusty trails a lot and constantly buying a new filter did sound cheep.
Before I did my tune up and gaskets I did run sea-foam in the crank case and through the vacuum lines/intake.
Here's what you're trying to get too. Mine at about 200k. Not too shaby!
