[VaSteve]

I was seeing a drip of oil in the garage which translated to the driveway now that the car is spending the winter outside for my 944 project. I thought it was the pan gasket, but Clarke tells me that the oil pan gasket leak is uncommon. An oil filter gasket leak will run down the slanted engine and look like it's coming from the passenger side.

If you remove the airbox, you can look at the (drivers) side of the engine and see the mess it makes. The gasket is $6 or so. Clarke (who is a professional mechanic at Manassas Motorwerkes) tell me that this is a job I can do in about 2 1/2 hours. The challenge is on! I started in the morning and was done in time for lunch.

I followed this guy's directions:
http://forum.e46fanatics.com/showthr...filter+housing

But, I have reposted and annotated here. There's about 12 pages of discussion on e46 Fanatics. Not sure why.

1a. jack the car up. It'll help
1b. disconnect negative batter lead
1c. remove air filter housing and MAF.
2. remove fan and fan shroud. (you don't have to do this step, but it makes finding the lower alternator bolt easy) - do this. You can't take off the belt with out removing the fan.
2a. Remove the belt. Untension it with a 16 mm socket and "
pin" the tensioner out of the way through the holes.
3. unbolt Power steering resevoir and lay over by the strut tower
4. remove the alternator. This step was a pain. Bentleys says to remove plastic cover and then remove main battery lead. On my car, the main battery lead nut IS made out of plastic. I think it was 17mm and was torqued on pretty tight. Don't forget to remove the electrical plug as well.
-The top bolt is hidden by the idler pulley cover. Just pry off cover w/ screw driver and remove 16mm bolt. The bottom bolt is just below the tensioner pully. 16mm as well. Did, you pin the tensioner out of the way? With both bolts removed, the alternator didn't want to come out. I had to wiggle it and pry for a good 10 minutes to work it loose. The alternator bottom bracket 'pinches' the oil filter housing. Just pry it off with a prybar or big screwdriver. I saved 9 minutes.
5. remove the Power Steering pump from the oil filter housing. There are 3 13mm bolts. The top 2 are easy. You have to get beneath the car to get to the bottom one. It mounts an angle bracket from the PS pump to the oil filter housing. You don't have to get under the car at all. See my photo below.
6. remove the oil filter housing. I read one DIY where they left the PS pump attached and just pried the pump from the engine block. I tried this at 1st and couldn't even begin to get the gasket off. It would be insane to attempt this without taking off the PS pump. It's 3 bolts. Leave the easiest one (longest) in until last.
-there are 6 13mm bolts. easy to get at. The VANOS oil banjo fitting on the back of the oil housing was 19mm. Not too hard to get to. remove 2 electrical connectors from the housing (you might want to label these, I was guessing when I put them back on). In true BMW style all the bolts are different lengths. As I pulled them out, I painted the heads with numbers to make it easier to put back in.
-a soft wrap w/ a rubber mallet seperated the oil filter housing from the engine block pry it
7. remove housing gasket. This was pretty tough. I used an ExactO knife to pry part of the gasket out to start it. The gasket was very hard and getting brittle. You'll see from the pic that I broke it in a couple places, but SLOWLY pulled all of it out in one piece. The groove where the gasket fits has "tangs" to hold it in place. Press the gasket all the way in. Hose everything down with brake cleaner or similar.
8. Install everything in reverse. Torque for the filter housing bolts is something of a mystery. I went w/ one source and torqued mine to 22Nm.
-New banjo nut and aluminum washers for the Vanos hose are a good idea

[VaSteve]

Photos and such (he's got a lot of photos too...)

Oily mess is to the left of the red alternator wire. Yes, I know it's hard to see.


Pinned the tensioner


The "hard to get" bolt on the PS pump


Engine side



Housing side showing the grooves


Reinstalled. You can see the white marks on the 6 bolts that I painted.

[Clarke]

Glad that you got it squared away Steve. Nice write up.

[Lupin..the..3rd]

Nice work, I suspect mine is leaking from the same. This will come in handy!

[ausgeflippt951]

Nice, thanks for sharing. Glad to see it's not too painful.

[Lupin..the..3rd]

Finally got around to doing this on my E46. There has been an oily mess on the underside of my engine for as long as I've owned it, and it wasn't clear where it was coming from. Reading through other forum threads led me to believe this oil filter housing gasket is a common culprit.

I printed off your instructions Steve, they were helpful. One difference I spotted on my '04, was the A/C tensioner required a T50 torx, and the serpentine tensioner wanted an 8mm allen. They must be different style of tensioner from yours.

A good tip I read on another site, is to open the oil filter housing top (as if you were going to change the filter) and let it sit like that for a minute. This will allow all the oil in the housing to drain back into the engine, making for much less of a mess when you remove the housing.

For re-installation torque of the oil filter housing bolts, the two numbers I found online were 18 ft/lbs if they are 8.8 grade bolts, or 25 ft/lbs if they are 10.9 grade bolts. Mine were 10.9 grade, so I used 25 ft/lbs.

Also did a few WYIT items. Replaced the two sensors on the oil filter housing while I had it out, oil temp and oil pressure. Much easier access than doing them in the car. 24mm deep socket required. Also I replaced all the hoses of the CCV system with the updated ones from BMW. Having all the oil housing stuff out of the way gave pretty good access to all of the CCV hoses, which are otherwise inaccessible.

I used new crush washers when reassemling the VANOS oil hose, part number is 32-41-1-093-596.

Here's the pics. First one showing the oily sludgy mess from the old leaky gasket. This one must have been leaking for quite a while to create such a mess. Second one is the two sensors and gasket, showing the part numbers. Third one is the bolts in order as they were removed. There's 3 different lengths. Bottom two are short, middle two are medium, and top two are 1 long 1 short. The short one on top is identical to the short ones on the bottom.

[VaSteve]

Originally Posted by Lupin..the..3rd

I printed off your instructions Steve, they were helpful. One difference I spotted on my '04, was the A/C tensioner required a T50 torx, and the serpentine tensioner wanted an 8mm allen. They must be different style of tensioner from yours.

My instructions were someone else's instructions annotated. Yes, mine is a 2004 as well and they switched to that giant Torx towards the end of the builds I guess. Nobody was more pissed than I was in the middle of a belt swap years ago to need that and not have it!

[magnetic1]

just to add, u guys should replace the belt tensioners and pulleys since those are accessible easily.

[HughA44s]

Thanks for the data - just did this along with the CCV replacement. A word of advice - When doing this gasket fix, spend some time cleaning up the housing, the block openings, and the vanos oil line. My vanos failed very shortly after doing this (POO14 I thinK). Did some research and found several cases that this happened - suspected cause is introduction of crap into the clean side of the oil supply to the vanos. I replaced the VANOS unit and she runs like a champ - better than ever. On the other hand, the 330 ZHP had 135,000 (bought used) with no indication of the vanos being replaced and it was rattling like mad. Also, the new unit got rid of the classic "ZHP" rattle. All and all a very successful DYI and a big savings on labor.