How come I had an 86 Mustang 2.3 with 175k (original engine and trans) that would do the same. Too bad the body was shot and it wouldn't pass emissions anymore as I had ripped everything but the converter off as a poor college student. Amazing what good maintenance and 3k oil changes will do.
Or the '87 Escort with 102k that I traded in on a 97 Cobra that was still running perfectly?
Buy good cars and take care of them.