Interesting: what's causing an oil leak on a new engine?! ;)

Update, with oil pan fully replaced.

First, I do want to thank @GregC1979 and Hybrid PitStop. They've been great throughout, and are fully reimbursing me. As they noted, if I were in SoCal, they would 100% have taken care of this. It's only tricky in that sense because I'm halfway across the country. And yes, they are learning more QA from this... and I would guess this will help prod them to do the blocks in house rather than outsource.

I also want to highlight @Georgina Rudkus comment: "I would be also concerned about how and if the technician cleaned out and chased bolt holes in the upper oil pan adapter."

Georgina nailed it. It's not hard to check this before installing the pan: a dental pick can discover any large blobs of material, and simply inserting/removing a new bolt will reveal uncleaned traces. The result in my case?

• Two of the bolt holes had small blobs of material. One was only about 1-2mm... the other about 3mm diameter..
• The bigger one, wouldn't you know it, was in the bolt hole where the bolt head came off, and the leak was centered.
• I measured bolt lengths and hole sizes. The problem becomes obvious: BOTH are ~16mm! In other words, other than the thickness of the oil pan and the sealant, there is ZERO room for other stuff.

With everything fully cleaned, and new pan and bolts / nuts in hand, the reinstall was quick and easy.

I'll mention one more item: when laying down the RTV sealant, what do you do about the bolt holes? I read many opinions on this, but one reality makes sense... and explains why both RTV instructions (in most cases), AND pre-cut gaskets, all do the same thing:

• You actually want an even layer of sealant all the way around each bolt hole
• The reason? So that pressure will be even on all sides!

Prius is again running like a champ, and no leaks.

BTW, 1500 mile EGR flow is ~15. Not sure about units... I have questions. That's for another day.

 

That's what I wonder as well. But these are 100% cleaned parts.
I'm wondering what else impacts this. Altitude? (7000+ ft here)- Temperature? etc...