That does sound really good for a 17y/o car. An 89 525i definitely has the M20 engine. It's a relatively easy to work on engine that had been around for ages. It has a timing belt (just mentioning it before someone else doesOriginally Posted by Qube
) that needs replacement every 50K miles or so, do the waterpump as well while you're at it or you'll be facing my current mess. In early/mid 90 (build year) the 525i received a much updated M50 engine.