Does anyone know a good upgrade seal for the e320cdi, had all my seals and bolts done 3 months ago and now No.2 is leaking again, I did use genuine merc parts but have heard that there is better washers that can be used
Yep, something not done properly, bad sealing surfaces, dirty thread (wrong torque), injector body not greased and made leaking possible again etc. etc. Often (too) thick washer is making things just worse, injection is disturbed by too high installation. Just remake the change of the seal.