I finally got the courage to change the Civic’s oil pan gasket.
This is what the bottom end looks like after 290,000+ km. Not as clean as I’d like, but not horrific, as far as I know.
It took a while to do it, but for the most part, things went fairly well. The process involves removing the exhaust pipe, removing two brackets, disconnecting the shift linkage, removing a metal panel, then actually removing the oil pan. I’m waiting ~24 hours before I refill it with oil, as per the Permatex Black instructions. The original oil pan gasket had some sort of gasket maker material on it (Honda-bond?) in four places, so I did the same thing putting the new one back in. Permatex Black says to wait 1 hour after applying, then torque things down to spec, then wait 24 hours before exposing to fluids. I really hope it holds and doesn’t leak. Although while I was under there, it looks like my crank seal is also on its way out. I think I’ll let the shop handle that when they do the timing belt, since they’ll already be mucking around in there.
Part of the motivation for doing the oil pan gasket is so I’m not as embarrassed when I take the car in for the other work it needs (timing belt, tensioner, water pump, and now a crank gasket). Things down there had been leaking for quite a while, and there was a thick layer of oil and dirt over everything. At least things are a lot cleaner now.