Om642 vacuum pump drive?
I basically got myself a c350 (om642) with a seized engine due to oil cooler gaskets leaking so wile searching for a new engine I have found one local but noticed that where the vacuumed pump is driven off the left inlet cam on my engine has a black plastic bung (oil blanking cap) fitted although the bolt holes look right the owner let me remove the bung I cannot see a way to drive the pump.
so I’m wondering if it’s a case of different cams or is it a simple sprocket swap?
im new to merc engines so probably going to get a load of stupid questions coming your way sorry
thanks in advance






