Passenger side oil build up

Hello everyone, I have a 06 4runner sr5 v6 with 225k and over the past year I have noticed a slight bit of build up on the passenger side under the valve body but it hasn’t been much at all. Today I went for my oil change and noticed a significant increase in the build up around the oil pan, too front of the tranny and even a little put onto the axel. I am very religious about my oil changes and checking my oil once a week and 6k like ago I didn’t have nearly this much build up and since then I never saw the oil level drop significantly.
Initially I thought that this was due to a leaky valve cover gasket but around the cover it looks dry. I then thought maybe the oil pan gasket but there is too much build up above the pan for that to be the only leak.
This is only on the passenger side of the engine bay, the drivers side it completely dry. Does anyone have any ideas where this leak could be coming from?
Thank you in advance.

 

Could be more than 1 issue. Have you carefully checked PS lines/pump. Also perhaps valve cover weeping thru gasket on that corner.
I would selectively clean 1 suspect thing with paper towels, cloth rag & simple green. Rinse with a squirt bottle with clean water.
Examine often. If not the source -do another suspect thing & repeat.

 

If it was mine I would buy a few cans on engine de-greaser and clean everything off and drive it for 30 minutes…….if it is creating that much of a mess it should show itself.

 

Sub'd for more info. Noticing the same on my 06 Limited. Also around 230k

 

Don't know if OP will see this. But if its leaking onto the power steering pump(passenger side) it is confirmed on mine to be a timing cover leak.

 

Most likely valve covers, I’ve replaced mine twice now.

 

Cost?

 

You can buy Fel-Pro at Advance Auto or AutoZone or buy factory Toyota, factory gaskets cost a bit more.

 

I'll look into that. I'm just trying to gauge what I'm looking at as I start to embark on fixing any and all leaks found.