I just took my '90 Civic into the shop: there are a variety of things wrong, and I knew it. Valve covers need to be replaced. Catalytic converter. Front axle. It hasn't had a tune up in, well, ever, so this is basically the first money that I've spent on repairs besides a fuel pump a couple years ago.
173,000 miles.
Engine and transmission are in great shape.
Whatcha think?