Oil pan mating surface corrosion on block

[oblique]

This is an unused Aaz block, everything looks fine on it except this one really bad spot...is there a good way to repair this or do i just rtv it each time?

[ORCoaster]

I wonder if you couldn't put some body filler in there.  One with more metal in it.  Otherwise, RTV if it holds.  I mean how often are you planning to expose it? 

[MeidleMose]

I wonder if that was a victim of the infamous incident in which several dozen AAZ blocks literally fell off the back of a truck at one of VW's assembly plants ...?

I've never used JB Weld for anything that large, but considering the rather non-critical location and purpose (relatively speaking), I might consider it for this repair. Build it up and then carefully file/sand it flat to match the adjacent flange area.

I would also recommend the installation of an oil-sump baffle/windage tray with heavy integrated rubber gasket:
https://www.urotuning.com/products/oil-pan-gasket-w-baffle-pre-1999-4-cyl-037115220b

[oblique]

I will clean it up best I can and just try rtv first, see how it goes.

Yes, origins unknown. I got it from a guy who got it from a guy who got it from...a guy. Came with a bunch more bits, although a bunch was AHU. Almost seems like someone was trying to put a motor together...maybe I will be that someone.

[fatmobile]

I use the reusable rubber, MK3 2.0 gasser oil pan gaskets.
 You could use great stuff to build up and attach the gasket to the block and put no gasket sealer on the other side so the pan would come off easily.
 Then you wouldn't have to reapply the sealant every time the pan came off,.. which I hope isn't often anyway, ha.

[oblique]

I do have some of the baffles Meidle linked to, guess Ill rtv that to the block.

The one super corroded pan bolt hole...i think the threads are gone, assuming i should helicoil that or tapmit up to the next size and forever be looking for that bolt.

[oblique]

Just measured the bores on this thing...all are right about 79.90mm at the top...whoops (pistons are 79.48). i didnt think bores tapered..either I have a new block that someone honed or a factory oversize, if those exist.