the 44k should clean out most of the carbon in your system. I believe the trick is to add it, then drive the car hard to get it to spit out all that carbon..
The oil, might be a little thick.
I use 20/50 as well, and my car makes a ticking on cold startup for a few seconds until the oil pressure builds up.
A Thinner viscosity oil might help it circulate more for you.
I would definately do some searchign on this site, you might find your question has already been answered.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.