[tilua]

Ok so I have about 105K miles on the car and recently replaced the valve cover gasket thinking that is where the leak is coming from. Also, I had the oil filter housing gasket replaced about 35K miles ago.

What is a possible leaking point that I should be looking at? Below are some of the picture of the underside of the engine. THere seems to be 2 separate area with oil leaks.

Please help

[smitty513]

oil pan gasket

[Flex68]

If you have done the oil filter gasket then will be oil pan .... I had leaks in same area we did the oil filter gasket first because that can drip and slowly end up down below but now it's still leaking from the pan area

[limitdown]

I had the same issue. Replaced oil filter housing gasket, oil cooler gasket, valve cover gasket. Problem persisted. Closer inspection with a bore scope showed oil pan gasket leak. It's not a cheap fix because many things need to be dropped to get in there. The bolts holding up the oil pan are single use aluminum stretch screws which must be changed. They also break easily so you must use a torque wrench to get them just right.

[N54Society]

Yeah I just got my oil pan gasket replaced last week so I recognize that mess. I had my OFHG and valve cover gasket replaced in August. Definitely an oil pan gasket. You need to lower the sub frame for this job.

[smitty513]

might as well replace your turbo oil drain lines while ur in there

[tilua]

Originally Posted by vbp6us

Yeah I just got my oil pan gasket replaced last week so I recognize that mess. I had my OFHG and valve cover gasket replaced in August. Definitely an oil pan gasket. You need to lower the sub frame for this job.

That sounds like a PITA. How did you keep your engine up before dropping the subframe?

[tilua]

It you look at the first picture, that is the second leaking spot. It looks like that is the air intake plastic hose. I suspect something is leaking there too. Is there any gasket for oil to leak there?

[mojobmw_e90]

My oil pans been leaking for awhile now. Should of done it when I had everything apart for turbos. Oh well, it's not causing me to loose oil so it's okay lol

[Jeff@TopGearSolutions]

At that mileage it wouldn't surprise me if it's the oil pan gasket.

You can clean the area thoroughly and check on it again. Right now there is so much it may be hard to diagnose 100%.

35K miles on the OFHG doesn't exude much confidence, that's plenty of mileage for it to fail again, sadly.

[N54Society]

Originally Posted by tilua

That sounds like a PITA. How did you keep your engine up before dropping the subframe?

This is how:

[Whit45]

Originally Posted by vbp6us

This is how:

I would definitely put a washer and nut threaded on top of that piece of all thread.

[=C=]

I had a odd oil leak as well and it turned out to be crank shaft front seal, that needed replacing.

[FL335]

OFHG leaks a lot of oil....could be that.... GL.

[Flex68]

Does anyone make a strengthen gasket so these pesky leaks don't come back as often??!

[tilua]

So I finally found the time to do this properly and it was a PITA. Not only I had to drop the sub frame but also unbolt the struts to drop it even lower in order to access all the bolts. I have a 335i convertible if that makes any difference. There was some sort of pump that was bolted onto the oil pan. Even after removing the pump, I was not able to remove the pan from the car.

I was able to get it done and save $1000+ but it was a biggest PITA and I work on cars a lot!.

BTW check out my redneck engine lift haha

[Jeff@TopGearSolutions]

The convertible has more bracing in the front end, I do know that much.

[Turbo_power4ever]

Originally Posted by tilua

So I finally found the time to do this properly and it was a PITA. Not only I had to drop the sub frame but also unbolt the struts to drop it even lower in order to access all the bolts. I have a 335i convertible if that makes any difference. There was some sort of pump that was bolted onto the oil pan. Even after removing the pump, I was not able to remove the pan from the car.

I was able to get it done and save $1000+ but it was a biggest PITA and I work on cars a lot!.

BTW check out my redneck engine lift haha

LMFAO!!!! shit, if it works it works.

[mojobmw_e90]

I did my turbos swap the same way. I used 3 pieces of 2x4 clamped together. Held the motor for entire week till everything was done. (waited on inlets for 5 days, turbos got finished in 15hrs)

[tilua]

Just want to update you guys that this was a success. Not a single drop of oil on the floor and it has been sitting in the garage for 2 weeks straight. whew!

[CruzBobby23]

Originally Posted by tilua

Just want to update you guys that this was a success. Not a single drop of oil on the floor and it has been sitting in the garage for 2 weeks straight. whew!

How many hours did it take to replace the gasket?

[mweisdorfer]

It looks like your oil pan gasket. I would check the backside of your valve cover gasket with a mirror first.

If you have a 335i –

You Will Need :
- 4 cans of brake cleaner
- Lots of paper towel
- Maybe pig mats
- Steel wool
- Emery cloth
- Kroil Oil
- New oil pan gasket
- New oil pan bolts
- New oil level sensor gasket
- Torx and e torx sockets
- Metric socket sets in a variety of sizes & drives
- ¼ drive, 3/8 drive and ½ drive "thin" ratchets
- Really Small & Large torque wrench
- Metric wrench set.
- Lots of swivels and extensions ranging from ½” to 6” in length
- A friend to help you mount the oil pan back into place
- 7.5 qts of oil and a new filter
- A weekend free of distractions
- Lots of patience.

Steps I took:

1) Remove the upper tray, which holds the cabin air filter
2) Remove the valve cover, plastic cover
3) Grind your tow hook down with a grinder so it will screw in all the way in the screw hole located near the oil filter housing assembly.
4) Screw in the tow hook
5) Draw a picture of the drive belt and pulleys
6) Set up engine support bar on the tow hook
7) Loosen up lug nuts on both front wheels
8) Put the car on 4 jack stands and remove front wheels; try and put it up at least 5 clicks up on your jack stands.
9) Remove the Belly pan and Transmission Pan
10) Remove the fan
11) Remove the drive belt with e60 torx socket & 18" power bar
12) Drain the oil and replace the filter
13) Unbolt the radiator pipe from the front of the subframe
14) Unbolt the power steering pump from the oil pan
15) Unbolt the transmission cooler lines from the oil pan in two places
16) Unbolt & unplug the headlight level sensor from the control arm on the drivers side.
17) Unbolt the sway bar from the subframe
18) Unbolt the power steering rack from the subframe
19) Place 2x4's under each disc brake
20) Unbolt the front struts
21) Wire or Hook the struts up so they just don’t hang there loose
22) Undo the brake lines from the strut assembly
23) Unbolt the black cross bar at its 4 outer bolts & loosen up the two center bolts.
24) Place a jack under the subframe where the jack point is
25) Unbolt the subframe with 18" socket and e torx socket; (6) 18" bolts and (4) e torx bolts
26) SLOWLY lower the subframe down and remove the jack.
27) Unbolt the 3 horizontal bolts located in the bell housing of the flywheel that holds the rear main seal. They bolt this housing to the oil pan to the rear main seal. There are 3 of them. 2 of them hold a clip that holds the O2 sensors wiring harness and oil level sensor wire. One of them is north of the clip I described above on the drivers side, and is sort of hard to get to.

28) Unclip the oil level sensor

29) Unbolt the many, many bolts that hold the oil pan to the engine and remove the oil plan.
30) Remove the Oil Level Sensor and gasket
31) Clean up the oil pan; use a brass brush and emery cloth or steel wool.
32) Make sure the area where the new gasket(s) will be is smooth as silk.
33) Use Glycerin on the flat gasket area before putting on the new gaskets
34) Re-install the oil level sensor with a new gasket.
35) Place the oil pan gasket on and zip tie it on with at least 2 zip ties (loosely)
36) Clean up the gasket area on the engine with paper towel and brake cleaner. plus steel wool.
37) Clean up the bottom, part of the engine (subframe) with brake cleaner and paper towel.
38) Install the pan with maybe 8 bolts hand tight (snug); maybe 4 in the center and 2 on each corner.
39) Carefully snip and remove the zip ties.
40) Rebolt to hand tight the horizontal bolts on the bell housing that essentially bolt the pan to the rear main seal and hold the clip for the post-cat O2 sensors.
41) Install the rest of the oil pan bolts hand tight or snug
42) Starting at the center, cross work and tighten down with a small torque wrench to 8nm plus 90degrees and the large bolts, on the south end of the pan, to 8nm and 180 degrees; don’t forget the 3 horizontal bolts (they are reuseable).
43) Put the rest of the car back together using the suggested torque setting on the subframe and what not (A Bentley Repair Manual does Help)
44) Put new oil in; it may take you 7 1/2 qts of oil because you literally drained all the oil out of the engine.
42) Start the engine up and let run for 10 min. Check for leaks.

Also, consider other items that are old that might need to be proactively changed while your in there, like O2 sensors. They are really easy to get to once the subframe is dropped. If your over 100k or near it, change them.

The following DIY's helped guide me:

http://www.bimmerforums.com/forum/sh...et-replacement

http://www.e90post.com/forums/showthread.php?t=1180020

One is on an n52 motor and one is on an n54 motor