The 4-cylinders are very strong.
Do you burn any oil? If so, and you get tired of it, a valve job may be in order, but not a necessity.
Has your timing chain ever been replaced? I hear they're quite bulletproof in the 4-cylinder engine, (never heard of breakage) but if it hasn't been done at this mileage it probably should be done!
Otherwise, I think just keep going until something breaks! Which probably won't happen..
Others here may know things which may need attention though
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black