Quick advice please

[sello]

Well quick run down. I have 08 e90 m3 and it has 106k miles well recently I noticed oil leaking from the oil filler cap so I decided to go to stealership and purchase one.. Well after cleaning all the dirt and installing the new cap I still have oil escaping! It looks a little rusty or crusty or both. My question is what should i stick inside he hole, cuz I'm thinkin sanding the rough surface might help get a better seal but I don't wanna anything falling into the engine

[anom3]

These cars are known to leak a bit of oil from around the filter cap.

Its a known issue that doesn't have a 100% solution.

Are we talking a "tiny bit" or more?

As far as what to stick in there... The correct way to go at this would probably be to take off the valve cover and do it with the valve cover off.

[bkdore]

Originally Posted by sello

My question is what should i stick inside he hole, cuz I'm thinkin sanding the rough surface might help get a better seal but I don't wanna anything falling into the engine

Get a sponge or a wax applicator pad, wrap it in duct tap or painters tape, sticky side out, and stuff it in the oil filler hole before you sand. That should keep the surface you want to sand available while blocking the dust from entering, and the tape is just an extra precaution from stuff falling in.

[sello]

Thanks for the tips, but considering it might be time for new valve cover gaskets that will probably be the best time to sand it.