Re: E28 87 535i is this an interference type motor?

Here is a link to some data on the M30 engine used in your car. This engine uses a timing chain to drive the camshaft. The question of valve interference is usually only pertinent to engines that use a life limited timing belt which requires regular replacement in order to avoid engine damage. Timing chains rarely fail catastrophically and always give a very noticeable audible warning if they are worn to the point where failure is imminent. Unlike the timing belts timing chains get longer as they wear and when worn appreciably they get so long that the chain tensioning mechanism can no longer keep the chain tight. When this happens the engine will emit a very noticeable BRRRRRRRR sound as the chains links bang into the chain guides. This noise first becomes noticeable with the engine idling because the chain tensioner is driven by oil pressure and the oil pressure is lowest at idle.