Anyone know about clicking noise below air filter on 300E?

[RRyan]

There is an odd, rapid clicking/tapping noise emanating from below the air filter and fuel distributer on my 1989 300E. It happens when the ignition is in the "on" position, even if the engine in not running. It continues after startup. It just started making the noise. The engine runs fine and the only symptom is the noise.

Thanks

 

[Benz 380 sel]

It could possibly be your bearings on your fuel pump.

 

[joe bloggs]

Not the fuel pump, its under o/s/rear of car, strange one, could be the Idle valve (controlled by the Jetronic ECU) or possibly cold start injector fault (controlled by fuelpump relay) or change over valve (black square thing on side of metering unit controlled by the jetronic ECU)

Take the airfilter off and disconnect the above one at a time.