Another EGR thread

From my perspective, near 200k with no previous EGR cleaning, head gasket is or will soon be toast.

Swap in a 2016 engine? That route is a bit more involved, and there's been unresolved overheat problems post swap.

How the oil consumption? Too soon to tell?

 

Last link in my signature is the full engine section.

(on a phone turn it landscape to see signatures)

 

I'm not sure what's the full list of sources and which contribute more or less, but the little puddle of gloop in the intake manifold has been a standard Prius feature all the way back to gen 1. The intake-valve timing used to achieve an Atkinson effect means some of the cylinder charge gets pushed back into the manifold on every cycle, including everything that was in that cylinder charge, including fuel and likely some oil vapor or mist from (at least) PCV. It's most likely the heavier fractions of all that stuff that end up condensing in the manifold, with the lighter fractions continuing on their way through the engine later.

If you dislike the puddle of gloop in the manifold, you can wipe or sop or slurp it out, which ensures that the gloop you see there the next time you look will be new gloop.

 

An oil catch can will reduce the amount of oil accumulating in the intake manifold nadir, how much dependent on the can's quality, and even quantity. I doubt it'll do much to reduce carbon accumulations in the EGR system though; a full EGR cleaning at least every 50k miles is my pick. Cursing Toyota for not road testing that problem child helps.