well good news, the new cap fixed the problem. sealed up tighter than a frogs ass! now for the confusion. its really irrelevant, just more for discussion since the issue is fixed but... I got the new cap, two o rings and a new filter. put it all together to drop in and noticed something. it was different then the current one and didn't seem to want to go in easily? now again, ive done these a bunch of time, but as I have not done oil in about a year on this since I only drive it about 7500 mi. annually, I looked at them both perplexed. at first I thought I got the wrong part. the one that was in there did NOT have a groove for the o ring to be seated in at the end of the threads. the new one did. I always remember these caps threading down flush with the o ring inside the filter housing sleeve. just like the picture on post #12 here. the one in the x was allowing the o ring to go all the way to the edge of the cap, thus squeezing the o ring between the cap and rim of the filter housing?? i've seen fitting like this before and just figured this was different then my other cars that ive had. I also stood in confusion scratching my head:confused: I started doing some searching and also looked at my e36 and the o ring is not visible at all, anytime on any pic or vid of the M54B30?? now i'm so confused? the cap is not broken at all, its just different. was this part superseded? vin confirms its the right part. ive been under the hood of this thing a lot and this was non issue for the last two and half years, so the cap was working. anyway, just curious to hear opinoions!

-Cheers

Fantastic news! Glad to hear you solved the issue.

I don't have a 3.0. The 2002 4.6 cap is flush with the filter housing. I am not sure if the you were saying the new one was flush or you can see the O ring when the new cap is tightened. Where did you order the parts from?

Either way--no leak no worry

yeah no worries! the new cap is flush. o ring is down inside the sleeve and not visible. I got the parts from a dealer. I still get almost employee pricing from when I worked there so i always go to them. it's the old one, that's been in use at least since I bought it 2.5yrs. ago, that you could see the o ring.

bimmer848, I had a similar experience when I replaced my filter cap this summer. I had fought with a leak around the cap for a while before I discovered that the o-ring on the cap had gotten flattened-out and I had been putting an additional o-ring over it for 3 or 4 years...:banghead:
I decided to buy a new cap, since I also suspected that the 2 small o-rings on the cap might also need replacing.


When I got a new cap, I also noticed that it wouldn't quite go on as easy as the previous cap, but I just tightened it hand-tight, and checked several times to make sure it wasn't leaking. I've been leak free ever since.

:thumbup:

the 2 small O-rings do go bad over time, I'm going to replace my cap on my next oil change (I only do it once per year) as I suspect it is the original 10 year old one, already replaced the fill cap too for good measure. No leaks knock on wood.

ill have to post a pic of the cap. its like it changed shape! so weird but all is good now.

-Cheers