I currently have the valve covers off on my '87 560SL & noticed that, at times, the timing chain appears very loose when I manually rotate the engine. (I know that the timing chain, rails, guides, and tension were all replaced very recently)

When searching thru various threads in this forum, I stumbled upon one that mentioned something about the tensioners working with oil pressure. Is this true ? If so, can this explain a substantial amount of timing chain "slop", when the engine is not running/zero oil pressure ?

Is there a wiki or a writeup somewhere that describes how these tensioners work ?

Thanks in advance,

Brian