Thanks for the response. I took the vacuam pump off last night. I now understand your response exactly. The bearing was very loose, about to fall out. It also explains the noise very well.
The vacuam pump was off my late engine and put onto the donor engine, which was an early '80 engine to allow clearance for the power steering belt and provide the correct connection to the vacuam line. Is the cam the same on both engines. Should I move the cam from the new style engine to the old to be compatible with the late pump?
As always, we very much appreciate your experience and expertise being shared on this forum.
Thanks and have a great day,
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in