Hopefully somebody can give some advice on this. My 300sd has been running like a champ but recently needed a new alternator and water pump. After replacing those when I started the car and went to give it fuel the o ring around the oil filter canister lid blew out, spewing oil everywhere. Seeing how it was about time for an oil change I purchased new filter o ring and oil. When I pulled the lid off one of the threaded studs used to secure it to the canister complete broke around the cast metal area it threads into. Luckily I have an 83 SD I use for parts. After swapping oil filter canisters, I replaced the o rings on the center shaft going through the filter and made sure the center shafts oil feeder line is clear...I can blow air thru it now. I replaced the big o ring under the lid with one that came with the filter. However this new o ring seems loose, falls out when I turn it upside down etc....overall doesn't fit snug like i feel its supposed too. When i try starting the car now everytime i gisve it gas the o ring blows out spewing oil too. Having tried combinations of other o rings and canister lids i have lying around, with no discernable difference and complete o ring failure. I have been looking at a few videos about oil changes on these cars and the o ring for the lid looks much thicker and snugs up nicely in the filter lids groove. So as it seems not to fall out when put back into the car. I'm going to investigate this o ring business today at the parts store and whatnot but if anyone has experienced something similar or the same, has any idea what could be happening here aside from the o ring under lid. You're time and input would be appreciated. Thank you