Just the same on any W124 And W126 and some 190E with the M103 lump ...And i did the same thing on my W124 .And the secret is to hold the injector bracket with another spaner so it wont move . And the injector securing allen bolt head was not holding in the wrench .Only way i could remove it was to damage the bracket to get a good grip on the allen bolt head .Then replace the bracket after . pick and pull was my way out .