just bought a beemer i know there is no cam belt, apparently there is a cam chain of some sort and i was wondering does anyone know when it needs to be replaced and is it a big job etc???? any advice appreciated. the car has done 100k and i dont know if its been changed

i had e36 325i and it had done 136000 when i got rid of it.It was still on its original cam chain.It only needs replacing if it starts to rattle and it is a major job needing some special tools.if there is a rattle from the front of the engine it could be either the cam chain or from the vanos system.yours done only 100,000 miles i would have thought it would be ok unless it hasn't been serviced regularly..

regards graham