I picked up a 1987 4 Runner with 25,000 miles on it five years ago. yes it was driven by a little old man. Engine and powertrain were excellent but body is going...frame ok.
He changed oil according to warranty book. i changed oil every 1200 miles. used diesel detergent oil...semi synthtic 0 W 30 for the harsh Canadian winters. A buddy gave me the oil so what the heck...i used it....I now beleive that the oil loosed up enough dirt in the engine and plugged an oil gallery that allowed a connecting rod berring to go. This was at
60,000 miles. i am now looking for a new motor. i will never use disel or semi synthetic oil again. Beware out there.