Ugh minor oil leak-picture attached

[Kristophe]

I previously had an annoying oil leak until I replaced my OFHG earlier this year and finally was able to enjoy a drip-free garage (as well as my parking spot @ work). In June I replaced my valve cover gasket after finding traces of fresh oil in two of the spark plug wells. Now I've encountered this new leak and I'm stumped where it could be coming from. I'm sure hoping it's not a bad main seal. The oil collects at one of the small bottom bolts where the tranny and engine join and oil even builds along a ridge and drips onto the sway bar. I've searched as much as possible without removing the the so-called stiffening plate. Any ideals?

[SMOKEY53]

Best bet will be to degrease everything - then check back in a couple of days to try and trace the oil leak upwards from underneath. Obviously the gravity brings it down to the lowest point (that bolt) and often wind rushing under the car blows it back across everything.

Unfortunately, I've had a similar leak and it was the rear main seal.

[Ricky Bobby]

How many miles on your X man?

Did you replace the 15 plug grommets when you did the VCG?

[Kristophe]

She's got 184K and no I didn't replace the grommets since they still seemed pliable and in decent shape. I don't find any oil leaking from around the VC. Since I'd like to change the fluid in my front differential I might as well remove the under plate to further inspect. Man O Man I fear its the Main $eal.

[X5only]

The OEM VCG come with the plug grommets.

[mferek]

What are the other symptoms of a failing main seal? Vibrations, noises, degraded performance, etc?

[Kristophe]

Get this; it has now been two days with no such leak(s).

[Kristophe]

And speaking of oil leaks. The other day I caught up with a very good friend I had back in High School and he has an '04 328 w/ M54 engine, same as mine. He bought it certified pre-owned in '07 with only 60K and how has 102K well maintained miles. He cannot get his car to stop leaking oil. He's had two OFHG (one under warranty) and he's had to foot the bill for the recent second one AND he's had to pay to have the oil pan gasket replaced in addition to I think one, if not two, value cover gaskets. Now he has a new mystery leak where when he goes up a steep hill or incline there's a slight fresh burning oil smell. Just wanted to share since we're on the subject. I consider myself fortunate. I'm reminded of STUNT and him pulling his entire 4.6 engine to correct all the assorted leaks.

I think I'll go ahead and order new grommets as a preventive measure.

[cn90]

This is a thread from 2014.

O.P. or anyone, any update to the diagnosis? I have the same leak at that particular bolt.
I am thinking a minor leak from the RMS.

[Kristophe]

I never could pinpoint the source. But it has to be the RMS considering the location and process of elimination. Considering the remedy (pulling trans) I just lived with it. I still have my X5 that’s going on 260,000 miles but she now is a spare vehicle. I’ve read of mixed results with certain additives specifically for RMS but never tried them. The additive softens the RMS material and helps to reseal. I’ve been iffy in the past with such additives and BMW engines. However at my high mileage what would I have to lose.

Let look and see which additive has the most positive reviews and I’d be willing to try it in mine.