Quote Originally Posted by 632 Regal
I would venture a guess that your motor mounts and trans mounts are bad and the engine shifted and somehow gave you such pleasurable sound, the give away was that it went away after shifting to reverse... that is where I would start inspecting altho the mounts are most likely toasted anyways.
I know its near impossible to diagnose from somebody's description of a noise. What I can say, is that it wasnt regular -not like a tappet, big or small end. Thats why I thought it may be a loose chain. Think my bedtime reading will be the Bentleys under headings timing chain, camshafts and followers etc. First job tomorrow though will be check the mounts!