Hello everyone, after doing a ton of research online it appeared that the only solution to replacing a leaking oil pan gasket on an E90 was to either drop the subframe or cut the gasket and insert it in either 2 or 3 pieces and use Permatex to seal the gaps. I decided to experiment and determined that if you're an average sized guy/gal (I'm 5'9" and 160 lbs) you can actually get enough room to drop the oil pan and reach everywhere that you need to in order to replace the gasket in one piece.
Unfortunately I didn't take a lot of pictures but then again there's not much to it. This repair is done at your own risk and I am not responsible for swearing, injury and/or death.
1. Parts required for my '06 330i with 6-speed manual transmission
- Oil Pan Gasket - 11-13-7-548-031 - $36.30
- Set of Aluminum Screws - 11-13-0-396-707 - $19.82
Above parts were ordered from BMW Cleveland which has some of the best prices going - ask for John and internet pricing
- Sealing Ring for Oil Level Sensor - 12-61-1-744-292 (bought this part locally so got ripped off at the stealer) - This ring is not typically required but it's a good idea to have in case you need to reach further into the oil pan during the gasket swap
- 6.5 liters of your favorite synthetic oil and a new filter (I didn't replace the filter as I unfortunately had a pretty good leak start within 600 miles of my last oil change )
2. Following are the tools I found handy
- 1/2" Socket with 17mm bit to engine drain oil
- 3/8" Socket with E12 Star Socket for Drain Pan bolts
- 3/8" 3" Wobble bit Extension
- 3/8" 6" Wobble bit Extension
- 1/4" Socket
- 8mm socket for belly pan bolts
- 10mm socket for oil level sensor and front splashshield brackets
- 10mm ratching wrench and 3/8" small close ended wrench (these work great on the oil pan bolts where you are unable to use a ratchet)
- Screwdriver (I used this for aligning the gasket holes later on)
- Bondo applicator or scraper of some kind (razor blade is also good) for removing old gasket if baked on
- Ratchet handle extension (this makes it easier to reach some of the bolts on the driver's side oil pan above the subframe)
- Snips to cut the old gasket for easy removal
Jack up car and make sure safeguards are in place. This is how I did mine:
Remove skidplate/belly pan using the 8mm socket
Remove from pan from under radiator (this will give you more room to work later on)
Disconnect oil return hose on driver's side of car (I actually used a long flathead screwdriver to press in the clip on one side and my finger on the other side - if you have strong hands you can probably just use your fingers
Unplug oil level sensor and unbolt ground wire using 10mm socket
Unbolt oil pan and discard old bolts. This is where you'll have to use a combination of wobble extensions and close-ended wrenches.
With the oil pan sitting on the subframe now comes the fun part. Carefully remove the gasket starting on the rear passenger side as this size has the most room and will give you a feel for what you're dealing with. BE EXTREMELY CAREFUL TO NOT DROP ANYTHING INTO THE OIL PAN! After I removed the old gasket I laid it on the floor to make sure all the rubber pieces were there as invariably some will be baked onto the oil pan. These must be removed with extreme caution as you don't want to drop anything into the oil pan. If you do, you have to hope that it's towards the back end of the car where you can remove the oil level sensor and fish them out that way or by reaching in through the top if you have fairly skinny arms.
Once the gasket has been fully loosened you can cut it on the front driver's side corner to make removal a little easier and remove it from the passenger side sliding it towards the back passenger side corner
Remove any residual gasket pieces. AGAIN USE EXTREME CAUTION TO MAKE SURE YOU DO NOT DROP ANYTHING INTO THE OIL PAN. I used my two scrapers for this and a razor blade may be ideal but will give you less to hold on to.
Once the old gasket has been removed, clean all of the surfaces on the block and pan (some of this will be by touch as you can't see it all). Also double-check to make sure you haven't dropped anything in the pan.
Install the new gasket. This is the fun part. You will need to feed the gasket in from the rear passenger side very slowly! You will encounter exhaust hangers, transmission, oil pan, oil pump etc. all on the way in. The metal part of the gasket can be bent as the only purpose it serves is to prevent the rubber from getting overly crushed when tightening down the bolts but don't bend it more than absolutely necessary as you don't want to damage the gasket. If you're of average size like me you will be easily able to feed the gasket under the oil pump by hand and up to the other side. That's actually the easy part.
Moving to the front of the car, carefully wiggle the gasket as far forward as you can. This is where it gets very difficult and you have to be very careful with the gasket as it has the potential to separate (look at your old one to see what I mean) as it will likely be bent downwards into the shallow part of the pan at the very front. You will need to reach a few fingers in here (very little space to do so) and fish out the gasket so that you can lay it on top of the oil pan. This took some doing for me and I tried initially with a coat hanger but ultimately ended up being able to do it with my fingers.
Double check to make sure the gasket looks/feels OK. I did that and wiped it down top and bottom just to make sure I had a clean surface to work with
I started inserting bolts where I could see holes already aligned but did not tighten anything down as you want room to wiggle the gasket and/or oil pan until you have everything properly situated. This is where I used by long screwdriver in the holes to help align things. Once I had all the bolts in I started snugging up bolts in the center of the pan working in a criss-cross fashion towards the outside corners.
Go around and make sure all bolts are snugged up tight. I'm not sure on the torque specs but if you have any experience whatsoever you'll have a pretty good feel for how tight they should be based on the type of bolt they are (aluminum) and how tight the old ones were. Besides you'll never be able to fit a torque wrench on most of them anyway.
Reconnect the oil return line, replace the oil level sensor (replace o-ring if necessary), plug in the connector for the sensor, connect the ground wire and reinstall the oil pan drain bolt if you hadn't done so at the beginning
Reinstall the front skid plate mounting plates and front skid plate.
Fill up with 6.5 liters of oil and take it for a test drive before reinstalling the main skid plate.
I hope I didn't miss anything and that this helps someone. If you can pull this off it will save you a LOT of hassle, expense, wheel alignment, etc. This repair can be done for less than $150 as opposed to whatever the stealer would charge (9 hours labor is what I've heard nevermind parts).