Facelift 09/2000 E39 M5 with annoying warm startup rattle which is harmless and doesn't affect performance but nonetheless very annoying. Remedy - retrofitting new design Vanos pressure accumulator and associated parts. For cars prior to 09/01/2000 the following is also needed: an electrical connector, wiring for DME and updating DME with the latest software to activate the new function. The new accumulator incorporates shutoff valve which prevents oil bleed off of the high-pressure chamber after the engine is switched off. Cars with production date after 12/01/2000 are equipped with newer Vanos accumulator. Cars between 09/01/2000 and 12/01/2000 have the electrical connector prewired from the factory but come old style Vanos accumulator. Cars prior to 09/01/2000 come with old Vanos accumulator and are missing wiring as well.