i am a new owner of a 2003 540i mtech and have been snooping around your forum for awhile. i have been a avid fan of bimmerforums but i thought i would pose the same question to you guys since our cars are similiar.
i just bought this car in amarillo,tx and drove it home to birmingham,al and it performed great. however now that im home and i start it cold i have noticed a loud rattle ike clanking that goes away after 3 or 3 secs. i know there is alittle valve chatter in these cars but this sounds more severe. bmw tech said no worries. i thought the dreaded vanos problems occurred only on the earlier models. i have also heard that the oil pump bolts were know to loosen or back out causing the pump to rattle on start up. my mechanic say that was on earlier models too. the bmw tech say to flush out the amsoil that the earlier owner just put in and go to castrol syn 10w-30. he said the oil alone would quiten it down a bit.
what do you guys think.
that noise scares the bejeezez out of me.
ps::::mileage is 102k
VANOs noise on cold start up is not uncommon for the S2, which is derived from your motor. If it goes away in 2-3 seconds, I wouldn't be concerned. It is simply the oil pressure building up. On the earlier M5's, an accumulator was added to prevent pressure bleed down overnight.
Not sure about the oil pump bolts, I remember something about that, but seems it was on older cars and not the M5. Can it be checked by dropping the oil pan? I wouldn't think that would be very difficult, even if just for your peace of mind.