Mercedes: Vacuum pump, mercedes benz 300d, castrol gtx


Question
Vacuum pump often doesn't pump when cold (below 32F); fine when warm.
Vac gauge shows check valve and brake booster OK.
Reving cold engine to 2500 rpm produces 20+"...
slowly.
Car:1987 MB 300D Turbo 3L 603.960 engine, auto trans,  204000 miles.
Motor oil is 10-40 Castrol GTX
MB 'cd' shop manual refers to later vac pump as having an extra oil hole. No other mention of pump.
It seems as though pump is 'sticking'.
Could this be an oiling problem or mechanical?
I'll appreciate any suggestions before I yank the pump.
Thanks in advance,
Steve


Answer
Stop driving it.
The vacuum pump is bad, needs to be replaced now; before it self destructs and costs you an engine.

PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1987 Mercedes Benz 300D Turbo
Part: Diesel Vacuum Pump

D3000-56042 Diesel Vacuum Pump Pierburg IN STOCK $307.72  
  
D3000-56042 Diesel Vacuum Pump Hella IN STOCK $307.72

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=merc...