Originally Posted by Squiggy

Thank you Andrew and everyone. I will probably replace the guides in the not too distance future but that is not something I can do right now due to my living situation. Here is why I feel I may need to replace the tensioner...

Three years ago at 98,000 miles I replaced my leaking valve cover gaskets, upper timing chain cover gaskets, and timing chain guide tensioner (man was that difficult for me to reach! but I have since purchase better tools). And of course changed the oil. I used a genuine BMW oil filter from Bav Auto (RIP) and Castrol Synthetic Extended Performance 5W-30. I live in a mild climate. It rarely gets too hot or cold here. I changed the oil from the bottom by draining through the pan. A year and 5,000 miles later at 103,000 miles (I don't put that many miles on my 4.6) I changed the oil again because it was turning black. This time I changed from the top with an extractor. It was my first time using an extractor. And I used a MANN oil filter. I don't think the extractor did a very good job because the oil was black again within a week. Lazy me has now waited another 2 years and 8,000 miles (now at 111,000 miles). I am about to change the oil again, from the bottom this time, as well as the tensioner. I think the tensioner might be getting gummed up. Once in a while (not every time) on a cold start I hear what I interpret as guide chain rattle. Mostly mild. Something a passenger might not notice. But every now and then the sound is more pronounced, enough that it has me concerned and I am taking evasive action. Also, I hear a very mild tractor like? sound at idle when I stand outside the car. I cannot hear in from inside the cabin. I can't recall if the sound has always been there. Maybe. But this whole deal is messing with my mind so who knows. I had not considered some of the sounds might be VANOS rattle. Will have to look into that too. Here is my plan for now...

Drain oil from the bottom (do not use an extractor)
Replace oil filter with Genuine BMW
Add Liqui Moly Oil Flush and run for 10-15 minutes *
Drain oil from the bottom again
Replace oil filter again with Genuine BMW
Run Sea Foam completing the recommended process *
Replace timing chain guide tensioner and gasket with OEM
Cross fingers
Start changing oil once a year or every 5K miles from now on