Don't know about your motor, but for my M119, timing chain guide rails are all plastic, could be some broken pieces fell into the oil pan, their color is dark amber.
99 BMW 540i 6-speed 110K Km
03 SAAB 9-5 wagon 80K Km
92 400E (Sold) 245K km
Still missing the days with the Benz, it kept me busy.