I had the same problem, I am not too mechanically minded but there is a rubber hose that goes from the air duct to the top of the engine it is only a short section but mine had rotted due to the build of oil, I found after replacing this the problem was sorted out, just take it off and take it to halfords and they can supply you with a section and then it is just a case of measuring cutting undoing the clips and fitting and no longer being poisoned.
Andy, April 2009
