What Is This Hole On A Top Of 1Zz-Fe Engine

Yeah, my 8th gen doesn't have the engine hook either - must be a 9th gen feature. I think even the 2ZZ-GE had the hook like that, though I can't remember off the top of my head.

As for cleaning aluminum - depends on how "clean" you want it. That piece has a texture from the manufacturer (think fine sand-blasted finish - satin finish) - so would take some abrasive material to clean that up. Some cleaners can also react with aluminum and stain it - so you have to keep that in mind. Unfortunately, most of the chemicals you buy will either clean up the oil/dirt or surface corrosion, but not both. I personally like Berryman Chemtool solvents for oil and grease - but will stain aluminum if you leave it on too long. To clean up the surface corrosion, a wire wheel works well, though you have to work the whole piece to make it look OK. I've tried various Scotchbrite pads and similar - but not abrasive enough to get the corrosion off. Some like steel wheel, some don't - last time I tried, it left little bits of steel wire on the aluminum - so that part now looks like rusted aluminum.

My '01 Prizm has the hook. Someone knew these engines would need to be taken out...

Interesting. I wonder if it is a regional thing (dealer or port installed), or where the engines were assembled (USA: TMM or NUMMI, Canada: TMMC, or Japan). On my 2002 Corolla, my VIN starts with a 2, so it is manufactured at the Canada: TMMC plant.

I also forgot to mention - friendly_jacek - that is an amazingly clean engine, at least compared to mine. Mine is completely salt pitted, rust everywhere, even though I periodically wash down the engine bay.