How tight should you tighten the oil filter cover?
This is on a 2008 C300.
Sorry for being in the wrong forum, but everybody is still asleep over in the correct forum.




When I change oil/filter, I just tighten the filter cap to where it's a tad more than snug.
The key to prevent leaks is to make sure the cartridge is fully seated and install the large O ring in the grove just below the caps lip (not up against the lip).
What appears to be the correct position for the large o ring is a grove next to the the lip.
Are you saying that your grove is further away from the lip, not right next to it?
UPDATE:
Thanks for putting that idea into my head about the groves.
Looking at the instruction sheet, it clearly shows the o ring going into the second grove. Since the instructions showed the grove just below the lip also, I'm satisfied that the instructions aren't for another model car.
I'm not sure how I did it 8 months ago.
Thanks for the help!!!
Last edited by JimPap; Aug 23, 2009 at 02:50 PM.




Also be sure the lube all the O rings with some oil before installing them.
I find it easier to add the new oil through the filter opening.
I also pull off the plastic engine cover (very easy to do) when I change the oil. With the engine running, this makes it easy to verify that there is not a leak.
Last edited by Serndipity; Aug 23, 2009 at 03:22 PM.
Wonder why MB even has that last grove next to the lip.
I let the car run in the garage for a while before taking out on the road for 5 miles. No leaks!!!
Thanks again for the help.




Typically, when the large O ring is improperly installed, there is an undetected slow oil leak (which is why I pop off the engine's top cover to inspect for leaking) that drips down the side of the engine and collects in the large splash shield underneath the front of the car.
After the leak is corrected, wipe down any engine/ suspension components bearing oil and remove the splash shield and clean it of any accumulated oil (otherwise the pool of oil will continue slowly exit through the shield's drip hole onto the ground for days).
It was from the oil filter o-ring. Apparently the one that comes with some of them is really soft and squeezes out after it has been running. Very frustrating. The oil continued to flow down the engine, and then back to the back of the engine, then flying onto one of the catalytic converters and burning off giving a frustrating oil burning smell.
Fixing that little o-ring (replacing with a new, good one), and then cleaning off the engine with break cleaner fixed it up, good as new.



