This is my first diesel mercedes.While driving at a constant speed it bucks at times. I was going to check the res flaps when i noticed that it is making a loud clicking noise when i raised the hood.The valve is going from open to closed very fast.I can't find if that is normal or not. Is there somewhere that explains how this system works? Thanks!

Roughly, see post #37 and beyond. Need Bosio nozzle feedback for OM606

It should not do what you describe.

If the engine was off it might have been the vacuum system venting vacuum that you heard? Over by the windsheild washer bottle?

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

It's the pressure regulating flap that keeps opening and closing, n ot the resonance flaps. Still cant find if that is normal