purchased a mann oil filter, part number HU727/1x. their catolog said it is for the 2002 c230. it came with the filter plus a large oring rubber gasket for the oil filter cap (part of engine). but it came with a small flat washer made of metal about a nickel in diameter. what is that for?

 

its a washer for the oil pan drain plug...(bolt)

 

thanks for the insight. i used the topsider technique through the dipstick tube. so theres no need for the bolt washer.