AMG was at the scammers today to have a suspected timing chain rattle looked into. After having the timing case off the chain and tensioner was given a clean bill of health. The dealership now has no idea where the rattle is originating from and wants a further 20 hours diagnostic time which involves taking the engine out and rebuilding! One of their suspicions is bottom end bearings, but surely this 'rattle' would be present all the time and not just at tickover. This is not what I’d class as a sick car. 99,000 miles, with full dealer history. It drives, stops and idles as it should, kicks down sweetly and goes like a proper AMG. Is my local dealer clutching at straws here looking for a big pay day, or have i actually bough a lemon? Advice and opinions desparately needed as i'm not willing to part with the guts of £3K on a suspicion.