I noticed the following on my 91 w/ 240K miles: 1) Creamy residue on dipstick; 2) flecks of oil in the expansion tank; 3) oil seems to become poor (bad smell, reduction in oily feel between fingers; and 4) spark plugs are spotless almost white.

# (2) may be a coincidence and (1) may just be condensation in the filer tube - it's 5-10 deg F here at night.

Car runs well, starts easily; minimal smoke at cold idle, none when warm; no loss of coolant; exp tank holds pressure overnight; no bubbles in expansion tank at any engine temp.

(3) and (4) are IME classic signs of hot water/ steam mixing with the oil - the oil will eventually become light brown. But with 0 coolant loss in 1K plus miles (since I've been watching it) I think this is unlikely.

I haven't checked the compression yet but will.

Am I missing anything.

--
240s: 2 drivers and some parts cars