As soon as I completed the performance testing phase of my custom tune I began the possibly lengthy process of assessing my timing chain issues. The cold start up rattle has continued to increase and I know that I have been lucky that the engine has lasted this long without catastrophic failure. I want to point out that I am disgusted with Ford for manufacturing a SOHC engine with the right timing chain located in the rear of the engine with extremely limited access. This coupled with the short life of the timing chain components reveals Ford's lack of quality, reliability and maintainability. It is indeed unfortunate for current and future owners that Ford has continued to manufacture this engine with this significant design flaw. My first task was to remove the right valve cover to determine what damage may have occurred. I have not previously detected any rattle from the upper rear of the engine so I assumed that the timing componets in this area would be in better shape than those in the front. Also, the oil lubrication to the rear timing chain components is superior to what it is to the front timing chain components. I was surprised at how many things block access to the valve cover and its attaching bolts. Eventually I loosened all of the valve cover bolts except for the outer rear one that is under the bulge in the cover for the rear cam sprocket. I purchased a set of 1/4 inch drive metric sockets and two wobble extensions to fit around the bulge in order to loosen the bolt. The photo below shows the underside of the right valve cover. I puchased the vehicle in May, 2009 with approximately 150,000 miles on the odometer. The tow truck driver I purchased it from (the vehicle was abandoned on the freeway) changed the oil just prior to selling it. I changed the oil to full synthetic after about 1,000 miles before starting the performance phase of my custom tune. The photo below shows the buildup of sludge on the camshaft and in the head. It's not as bad as some I've seen on the forum but certainly nothing to be proud of. At least drainage from the top to bottom was not blocked. The photo below is the best picture I could get of the timing chain components without using a mirror. Please note the obvious lack of tension (slack) on the inner side of the camshaft sprocket as the chain drops toward the jackshaft. I could easily deflect the chain toward the center of the block more than one inch with my fingers. I did not feel the presence of a guide but my reach was very limited. My only hope is that the tensioner on the outer side of the head has a broken internal spring. I encourage every SOHC V6 owner to change the upper tensioner every 75,000 miles or less to reduce cassette damage. However, periodic replacement of the tensioner will not prevent guide wear on the traction side of the chain. I will clean the chain area with engine flush and puchase a mirror for better visibility. I'll also remove the external tensioner and compare it with a new one I have. The photo below shows a new rear upper cassette. I suspect that most of the plastic "ladder" is missing allowing the excessive chain deflection.