Been working on my car today, cleanign up some oil spills and replacing a couple EGR gaskets etc and I noticed that there is a low pitched thumping noise coming from around the intake area which become more aparent when you pull the flat pipe from the airbox and have an exposed opening and it becomes really loud.
Its a 2006 BPW engine with 70k on the clock cabriolet S-line
I found a few threads on the web about camshaft/tappets wearing such that they dont quite open/close properly causing, what I seen people refer to as, 'blowback'.
If this is the case, what do I need? I have **** loads of tools but what about any special tools etc? Im pretty confident in doing the work myself.