Ok,
I know this has been discussed to no end, but I had what sounded as a tensioner starting to fail, and replaced it with the new updated m44 version (febi/bilstein) brand. Installed it unsprung, as discussed in many threads.
I now have a fairly noisy (stone cold startup) chain rattle, and decided to pull the valve cover and inspect.
Sprockets look perfect, rails look great, and chain is in very good shape as well, with no signs of slapping the v/cover or timing chain case.
Now.. I'm thinking I have a lazy tensioner, since the noise goes away after warm up (3-5 mins) or normal driving.
Letting the car sit for 10-15 mins yields this noise again (not as severe, but noticable) upon start up.
This engine has been over maintained since new by the PO, and I have buckets of records. It's lived on 1040 and 2050 redline oil since 36k miles.
I'm getting ready to order an OEM Genuine BMW m44 tensioner, since this one seems a little notchy and lazy.
How smooth did your (new) tensioner move in and out ?