hi my name is dean and im new to the forum and also ive only just bought my first c-max about a week or so ago , its an 05 reg 1.6tdci 110 bhp version , it has plenty of power and myself and mechanic friend of mine have just serviced it , the problem is its making aloud tapping or knocking sound but its only seems to be coming from the first injector closest to the drivers side my friend doesent seem to know what it is,can anyone help also can you tell me why that first injector rather the pre-heater is not as tall as the others or are they all like that cheers for any help dean