knocking or bang

Bear with me I hope this makes some sense. Bought a second hand Vito CDI 108 yr 2002 for Taxi purposes – it was previously being used as a taxi but in a different town with probably smoother roads. I often transport 7 passengers and the rear suspension is proving an absolute nightmare –...

hi on my 1994 E300D W124, when i am driving along, if i take my foot completely off the accelerator and then push it down quickly, say to about half way, i get a bang/knock that appears to come from the back of the car. any ideas what this could be and how to fix it? its fine to drive...