My money is on your power steering fluid being low. It, like the transmission has temperature gradations on the dipstick. Check it before starting the engine, if it doesn't register on the dipstick, add enough to bring it to the lowest mark. That probably won't be much fluid....Start it, drive to a place where your front wheels are on gravel or sand (you are looking for a place the does not give the front tires a good grip) crank the wheel from lock to lock a couple times. The noise should go away. Drive home and recheck the fluid which is now closer to working temp. Adjust fluid as needed.
Bob
I did a search to add to this thread.
I have a 2008 Chassis Roadtrek 2009 build RS A 2500 with 41,200 miles. I was getting identical symptoms as the OP.
At temps below 50F, I got a loud groaning, howling and/or vibration for the first few miles. It always went away after about 5 minutes.
The noise never occurred in the afternoon, or after warm up.
I noticed the other day, that I kind of heard the same noise when the steering was on full lock. This prompted me to check the PS reservoir WHICH WAS EMPTY.
Anyways, I got a bottle of MBZ Q 146 0001 for $12 at the local dealer and put in about 200 ml. With temperatures at 46F this morning in Tampa, I started the coach and did not hear any noise whatsoever from the front.
Hopefully this was the issue.
Appreciate finding this thread, just hoping it will help out someone else with the same issue on an older Sprinter.