[carguy138]

January 31 UPDATE: Looks like I may have had a pocket of oil somewhere that I missed during cleaning. Wiped off the oil residue, sprayed the area down with a hose and dried it off. Drove about 50 miles and no signs of oil leaking. Talk about a great feeling!

Thanks again for the replies, it was much appreciated.

Just finished a fairly substantial job on my 2011 N55 335i xdrive and took it for a quick 5 mile drive last night. Everything felt great except I have an oil leak that I cannot track down. Keep in mind everything had been scrubbed down with simple green and brake cleaner, so any visible oil residue occurred in the 15 minutes I let it idle and during the brief test drive.

After getting the car back in the air last night I looked everything over and noticed a little oil at the bottom of the transmission/motor housing location (can see on the pictures) wiped everything down. Checked again this morning and took these pictures.

At first I thought it was coming from the oil pan gasket so I ordered that last night. After looking at it this morning, there is fresh oil about 12" above it. The VCG was done recently and I cannot see any signs of it leaking (looked with LED flashlight/mirror combo). When the VCG originally failed, it smelled horribly because the oil would drip on the turbo housing. As you can tell from the under body (first pic), the oil leak was fairly substantial but I attributed that to the OFHG leak. No burning oil smell these past few months of driving the car.

Fresh oil appears to be coming from well above the oil pan gasket on the turbo side of the motor. The underside of the turbo manifold where it mounted to the block looks a little wet as well. Front of the motor and drivers side (below intake manifold) are bone dry. Also everything around the oil filter housing is bone dry too. I also popped off the plastic transmission cover to see if there was any oil residue from a blown rear main seal but everything is dry in there (at least from my vantage point).

VCG replaced by BMW dealer in fall of 2016 (15k miles ago)

I just replaced:
-Oil Filter Housing Gasket
-Oil Cooler Gasket
-new Front Diff/Transmission/Transfer Case/Rear Diff fluids
-New water pump/thermostat/coolant
-New serpentine belt, tensioner, pulleys.
-Oil change

Really stumped here and any suggestions would be hugely appreciated!

The first pic of the under body was to show how bad it was before I tore into it.
second pic is the front of the motor, bone dry but was a mess before due to the OFHG.
Third pic is below the intake manifold, bone dry but was also a mess due to the OFHG.

Fourth pic and down are all the pictures I took this morning of the current leak.

[feuer]

Oil pan. This being Xdrive would be tough...

[carguy138]

Originally Posted by feuer

Oil pan. This being Xdrive would be tough...

Thanks for the answer. This is what I thought, but I see oil well above the seam where the oil pan gasket sits. Like 8-12" above it.

[feuer]

Originally Posted by carguy138

Thanks for the answer. This is what I thought, but I see oil well above the seam where the oil pan gasket sits. Like 8-12" above it.

If that is on the right it is because the engine is tilted and molecular gravity will cause oil to travel up from vibrations. Could be something else as rear main seal but oil pan will be my #1 suspect.

[carguy138]

Wow I never would have considered that. It is coming from the right side.

Kinda crappy considering I only have 54k miles on the car...

[rich_mane]

Possibly one of the turbo oil lines are leaking?
Like #2 here: http://www.realoem.com/bmw/enUS/show...diagId=11_4474
Could maybe just replace the leaking o-ring if that's all it is.

Other than that it would probably be the oil pan or rear main^

[carguy138]

Originally Posted by rich_mane

Possibly one of the turbo oil lines are leaking?
Like #2 here: http://www.realoem.com/bmw/enUS/show...diagId=11_4474
Could maybe just replace the leaking o-ring if that's all it is.

Other than that it would probably be the oil pan or rear main^

That would be awesome if that's the case. I will check tomorrow. Thank you! Trying to get a mental image and from what I remember it was pretty tight in that spot. Any idea what needs to come out to get better access? Would ideally like to spray it down with brake cleaner (non chlorinated), wipe off the excess oil, and let it idle to see where the oil leaks.

I have the oil pan gasket/bolts on the way and have been reading up on the job. Do able but would prefer not if possible. Same with the rear main seal. That looks like a royal pain.

[juld0zer]

Rear main is easy. Sump gasket on an Xdrive is a mission.

Before you panic too much, id suggest taking the belly shields off and cleaning again. Use a good chemical degreaser, hose it off (dont let it sit for long periods as many degreasers attack aluminium), let it air dry then brake cleaner.

Focus on the areas under the intake manifold as there are many pockets where dirt and oil will pool once you hit it with degreasing agents. It literally is a case of chasing away the dirty liquid with fresh brake cleaner. Compressed air helps but just be careful not to accidentally find a 12v positive connection

My guess is that you had a few big puddles of dirty liquid and driving the car has shifted it. Airflow into the engine bay and from the fan will blow it all around.

[MTK24]

54k miles and you already replaced VCG, belts and now oil pan gasket?

is your car stock? I'm surprised to see this many issues on a n55 x drive

[carguy138]

Originally Posted by juld0zer

Rear main is easy. Sump gasket on an Xdrive is a mission.

Before you panic too much, id suggest taking the belly shields off and cleaning again. Use a good chemical degreaser, hose it off (dont let it sit for long periods as many degreasers attack aluminium), let it air dry then brake cleaner.

Focus on the areas under the intake manifold as there are many pockets where dirt and oil will pool once you hit it with degreasing agents. It literally is a case of chasing away the dirty liquid with fresh brake cleaner. Compressed air helps but just be careful not to accidentally find a 12v positive connection

My guess is that you had a few big puddles of dirty liquid and driving the car has shifted it. Airflow into the engine bay and from the fan will blow it all around.

You were right, that's exactly what it was! I had done quite a bit of cleaning and guess I missed a spot somewhere.

[carguy138]

Originally Posted by Vampire335i

54k miles and you already replaced VCG, belts and now oil pan gasket?

is your car stock? I'm surprised to see this many issues on a n55 x drive

Pretty much stock except for a JB4.

Car runs well but unfortunately cheap BMW rubber/gaskets are the problem. One would think the added expense to fix the problem (seems to happen on ALL platforms) would serve them well in the long run.


Just a shame that they generally make a solid car but completely cheap out on the rubber/gaskets. If they took a tenth of what they spend on free drinks/food in the dealer waiting rooms and applied it to creating much longer lasting gaskets, they would be very well served. Increased perception of reliability by consumers and less waste (all the fluids/labor/cleanup/logistics/etc).

Fortunately my car has been pretty good but after 54k miles I've had to replace the Valve Cover Gasket, Oil Filter Housing Gasket, and Oil Cooler gasket.