cam lobe/valve adjustment tool
Yes you are right i just need to take the valve cover off, this knock came on slowly and my daughter complained of dogeshness. I happen to own an x5 and two early ix's do you know what tool it is?
I know what the tool is, but I'm away from my factory manual set(sorry). You might check one, if you can get access to someone's. Toyota lists all the factory tools (and there are many, especially compared to BMW) in the manual. Unfortunately, my manual set is back in the states right now. What weight oil is being run in the 4runner? Generally, 10w-40 runs those V6's pretty quiet. I find thinner stuff really brings out a lot of noises.
If it needs an adjustment, you might see what a dealer would charge, as with the "M" cars, you need a full shim set as well as the cam lift tool.
On the "dogishness" , you might check
1)timing
2)fuel system(filter, injector o-ring/housing vac leaks, pressures)
*ethanol is doing a number on these trucks
3)drive line mounts and rear suspension mounts/bushings can really make a huge difference in how the truck accelerates(direct, connected feel)
4)tune-up(these trucks need regular plug changes, I do ours annually)
regards