Blowing oil from the filler cap

Hello All,

My 2004 M3 had oil leaking around the filler cap. I know this can happen so I replaced the filler cap. Now I still have oil leaking around the filler cap. Quite a bit in fact. Like about a liter every 200 miles. That stuff is expensive and you don't look cool when your ride stinks of burning oil and has smoke coming up around the hood.

So, did I just get a bad cap, or is there some other malfunction that might force oil out around the cap gasket? I'm stumped.

Thanks!

Look for other problems like a bad CVV or a vacuum leak. Also check your intake boots for cracks.

I'm not sure what the CVV is. I will look for vacuum leaks and inspect the intake boots.

Thank you.

Originally Posted by p.mcconnell

Hello All,

My 2004 M3 had oil leaking around the filler cap. I know this can happen so I replaced the filler cap. Now I still have oil leaking around the filler cap. Quite a bit in fact. Like about a liter every 200 miles. That stuff is expensive and you don't look cool when your ride stinks of burning oil and has smoke coming up around the hood.

So, did I just get a bad cap, or is there some other malfunction that might force oil out around the cap gasket? I'm stumped.

Thanks!

I had the same issue with my new aluminum oil cap, all I did was take it off, put it back on slowly and looked at it at eye level while doing so - - and twisted it slowly till it was tight, then took it off and did it again and carefully/slowly at eye level tightened it till firm. no more oil leak. Even when I got my car back from an oil change, same thing happened - - I did the above and no more oil leak. Slapping it on and twisting it won't work with these aftermarket caps, you have to be precise.

The CVV is the crankcase ventilation valve, BMWs version of a pcv valve. It is located under you intake and can cause oil problems with the engine if it gets clogged or frozen.