Hy to everibody and thanks for all information in this forrum.
my car a CLK 430 1998 last week decided to die and it was the fuel pump.
After some test i decided to change the pump with one new MB and the filter , the car started again even if it takes some times before turning with 8 cil..
Now the car seem to run weel but ti can hear some little noise from the fuel pump like ''Z-ZZZZZ-ZZ-ZZZZ-Z'' i mean that the noise is not constant abut intermittent and not reular.
So iwas thinking that tha pump was sucking some air ^while the internal pipe inside the tank ,for this i filled at max the tank and tried.......the noise is the same.
tha car seem tho miss some power only between 5000 and 6000 rpm but i ma not suer because i ma really not used to drive klike this..
i would like to ask if sombody can tell me where is the FUEL PUMP RELAY in this way i willl chek if the power supply is good.
Can someone help me? Do you have some more test to suggest me?
Many thanks
Alberto

Sorry may be my English + explications are too bad..........