I don't think your reply about the loose timing chain on my 300SD was correct. You said that a loose chain was OK. This is not true, the spring in the tensioner is supposed to take up the slack when engine is not running and at start up until oil pressure is applied to the pressure bolt.
When I took my chain tensioner off I found that the pressure bolt was siezed in the housing thus causing the clearance between the pressure bolt and the chain rail.
Had I taken your advice and not checked the tensioner, I could have done serious damage to the engine.