My engine was shaking and rattling on shutdown which gave me a feeling of dread thinking it was DMF failure however there were no symptoms when driving even if accelerating from 800rpm in 6th gear, I decided to remove the motorised throttle valve for cleaning having read that it could cause this problem if the carbon build up prevented it from closing properly.   I was surprised by how clagged up it was, I thought I had left decokes behind me decades ago but it has had the emissions fi