I have a 91 300SEL with 113000 miles. Recently (1 month or so) I have noticed that the car makes a loud humming noise while running. The noise starts when I crank the engine over and is present on the last position of the ignition switch before the engine cranks. I tracked the noise and the noise seems to be coming from the passenger rear area. Fuel pump gone???
Should I replace ASAP or can I wait?
Other diagnostic checks?
Instructions on how to change the fuel pump if this is the culprit would greatly be appreciated!!!
91 300SEL 113000mi