This affects these 3.0 straight six diesel engines up to 2004. From: www.honestjohn.co.uk/carbycar/bmw/5-series-e602003...d : “On all diesels, 4 and 6 cylinder, intake manifold swirl actuators can break off and be ingested by the engine, wrecking it to the tune of as much as £12,000. However, in some cases (one of a 2004 530d to which this happened in 2009), BMW fitted a new engine at a customer cost of £2,000. One school of thought says that swirl flaps can be discarded entirely, though this will make the engine less efficient. The first sign of an impending problem with the swirl flaps is very poor idling. www.pmwltd.co.uk has a solution, which is a billet aluminium blanking plate that is substituted for the swirl flap. Well worth doing because it could save the cost of a new engine or having to scrap the car.”