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1998 528I Oil Filter Housing Gasket & “Freeze Plugs” Repair (E39)

192K views 97 replies 45 participants last post by  Bmwe39528i 
#1 · (Edited)
DIY: 1998 528I Oil Filter Housing Gasket & "Freeze Plugs" Repair

- I have what seems to be an oil leak along the Oil Pan Gasket. To replace the Oil Pan Gasket, it is a massive job on the 6-cylinder engine!!! So I went to the BWM dealer and they say that they virtually never sell an Oil Pan Gasket!
But they fix quite a bit of Oil Filter Housing Gasket, actually they have a whole bunch of these gaskets in stock!

- I did a little more research and apparently the Oil Pan Gasket is made out of some very tough material with a steel re-enforcement and should last into 180-200K miles. So I figure out common things are common and rare things are rare!

- As it turns out, I have leak at both Oil Filter Housing Gasket and "Freeze Plugs". It is an easy DIY, roughly 3-4h job.

- To my pleasant surprise, I have no more oil leak after one week, so those who think you have a leak at Oil Pan Gasket, think again, it is likely the Oil Filter Housing Gasket and "Freeze Plugs" Leak!!!

* The issue of "Freeze Plugs" leak was discussed here:
http://www.bimmerfest.com/forums/showthread.php?p=4701933
Instead of removing the "Freeze Plugs" and tap threads for an "NPT Thread" Plug, I decided to use an M7 bolts + washer for repair, and it works great (see below).

To check for a Freeze Plug Leak, use a mirror and flashlight:



* Info on drive belt layout and belt tensioner (32-mm thin wrench for Fan Clutch Nut <REVERSE Thread> and 5/16" Allen wrench for tensioner):
http://www.bimmerboard.com/forums/posts/199986

* Info on how to remove Air Filter Housing is part of my DIY for ICV, CCV etc.:
http://www.bimmerfest.com/forums/showthread.php?t=379225

NOTE:
- Check realoem.com for your PN.
- Check your belt layout and make a diagram before taking it off.
- The PN for my 1998 528I Oil Filter Housing Gasket is 11421719855 ($5.00 at BMW dealer).
- Observe Torque Values (look it up) for different bolts.
M8 bolts = 22 Nm (Oil Filter Housing)
M10 bolts = 33 Nm


---------------------------------------
PART I: OIL FILTER HOUSING, ALTERNATOR REMOVAL

1. Disconnect Battery Positive Terminal in the trunk (10-mm wrench, be careful not to short with the ground bar!)

2. Remove Fan Clutch: 32-mm wrench. Note it is REVERSE thread!
During re-installation if you have difficult threading the Fan Clutch Nut back on the Water Pump bolt, you can use my "Poultry Cord" trick:
http://www.bimmerfest.com/forums/showthread.php?p=2758628

Use 5/16" Allen wrench for tensioner to remove belt.

3. Disconnect the DSC System Connector.

4. Remove the Air Filter Housing/Air Mass Meter as a Unit. Remove the 10-mm bolt and clamps and wiggle the whole thing out watching not to damage the Intake Rubber Elbow.

5. Remove the 13-mm Bolts the PS Reservoir and set it aside:



6. Alternator is mounted by two (2) 16-mm bolts. The UPPER Bolt holds the Pulley.
The positive cable connection is a 13-mm Nut.
- D/C connector
- D/C Cooling Air Intake
- Then Alternator comes out (It swivels on the LOWER bolt).
- During re-installation, use a smaller rod or screwdriver to help guide the Alternator back on the slot.



7. To remove the Oil Filter Housing:
- Disconnect VANOS Banjo-style Oil Line attachment to the VANOS using 19-mm wrench.
Do NOT lose the 2 aluminum washers, I re-use these washers. Torque for this 19-mm Banjo Bolts: 32 Nm.
- Optional: Remove Tensioner (Yellow Arrows) using 13-mm sockets. You don't have to do this step as it can be left attached to the O.F. Housing.
- The O.F. Housing is held by a total of 8 bolts.
- The six (6) 13-mm bolts have different lengths: mark them #1-6 to avoid confusion. In the event that you forgot to mark them, no worry, I laid them out in order as shown.
- Remove two (2) 13-mm bolts (# 7-8) on top of the PS Pump.



8. Now the O.F. Housing comes out easily. Remove old gasket and clean the mating surfaces to make sure it is spotless for re-installation.

9. If you decide to de-grease this area, go slowly!!! Stuff a rag inside the Engine Housing to prevent dirt or water from coming in. Avoid garden hose or pressure washer for obvious reasons!!!
- Wipe it clean with a rag and Q-tips so no oil is left behind.



10. Have a look at the O.F. Housing:
- Note the Oil Pressure Sensor on the back side.
- Note the Engine Oil Anti-Drain Back Valve.
- When installing new gasket, I use a thin smear of grease to seal any imperfection (this is just my way, you don't have to do it).
- Check both the mating surfaces to be sure it is spotless before re-installation:



- The Gasket barely sticks out (maybe 0.2 mm), so avoid using additional gasket maker here because it can potentially affect the Factory Gasket sealing:



Re-installation:
- Straightforward.
- Note all connectors and re-install them.
- Watch torque values.
- Wipe all oil leak in engine compartment and along oil pan gasket area so you can monitor these areas later.
- Re-connect Battery Positive Terminal.
- Start engine and check for any oil leaks at Housing or Banjo connection.

Congrats, you just spent $5.00 and saved some 4h of labor charge at dealer or indy! Now let's move on to fixing the Oil Filter Housing Leak itself.

---------------------------------------
PART II: OIL FILTER HOUSING "FREEZE PLUGS" LEAK REPAIR

- After the following repair of "Freeze Plug" Leak, my car is bone dry, not a single drop of oil leak!

Parts List (All of these can be obtained at Ace Hardware Store) for about $12.00:
- Stainless Steel M7 x 10 mm bolts; qty = 2.
- Optional: M6 x 10 mm bolts; qty = 2 for "dry fit".
- Stainless Steel Washers O.D. = 1-1/4"; I.D. = 5/16" (5/16" = 8 mm to accept the 7 mm bolt).
- Red LocTite, small tube
- Permatex Black RTV Gasket Maker
- Roofing Black Asphalt Caulk




- The "Freeze Plugs" are actually not "Freeze Plugs" but basically Welch Plugs that are stake-punched in from factory to close off holes from casting. It should have been plugged with bolts and washer (later models use bolts and washers). But this design of "Freeze Plugs" is known to cause oil leak in different BMW models.
- A new O.F. Housing is $330!!!
- The leak from my "Freeze Plugs" is about 4-5 drops on the driveway every night. But there is more leak than that (oil blown off on the road and collecting under the oil sump).

1. The hole in the "Freeze Plugs" is made from Aluminum and has a diameter of 6 mm and the M7 bolt fits perfectly.
- Do a search on tap and die of bolts and nuts, but as a rule, the hole to be threaded is always a bit smaller than the new bolt. This is because the M7 bolt has a diameter of 7 mm measured at the tip of the pitches but the measurement at the valley of the pitches is about 6 mm.
- To tap new threads, you can use a tap and die set but if you don't have a tap/die set, no problems. Use the M7 bolt to tap it with 1/4" ratchet. Keep steady pressure and maintain perpendicular path. The bolt is Stainless Steel and the Plug is Aluminum, so the bolts makes new threads with no problem (this is what I did).
- Tap a few turns at a time while removing the metal fragments. The hole is about 5 mm deep.
- Clean the hole from any debris:



2. Now use the smaller M6 x 10 mm bolt to make sure it fits nicely. The idea is: the washer should be 1mm from the housing. This is because this space will be occupied by Permatex RTV Gasket Maker, which will cure into a rubber-like material:



3. Now fit the washer and the M7 x 10 mm bolt as a "dry run". When the bolt is completely in, you should see a 1mm gap between the washer and the housing. Do NOT over-torque this M7 bolt, very easy to strip it!
- Now, remove the bolt and washer and proceed with the sealing job.

4. Apply Roofing Black Asphalt Caulk at the edges. This is where the oil leak happens. The Black Asphalt Caulk will seal it nicely and has a wide range of temp tolerance.

5. Now apply Permatex RTV Gasket Maker as shown, leaving the hole alone. Use Q-tips to clean the hole:



6. Place washer then rotate it a bit to spread the RTV sealant. The Permatex procedure calls for letting the sealant cure for about 2h before tightening the bolt. However I install the bolt right away, read on***8230;...........

7. The M7 x 10 mm bolt: apply a drop of LocTite on the thread and a very small drop of RTV sealant near the bolt's head. Again, use 1/4" ratchet and do NOT over-torque this M7 bolt, very easy to strip it!

8. When the bolt is fully seated, you should be able to rotate the washer because there is 1 mm gap filled with RTV sealant (but after 24h of cure, the RTV sealant will be rubberized and you should not be able to rotate the washer).
- Clean excess RTV Sealant. This is what it looks like prior to re-install:



9. The key thing: you can install everything back in the car but don't start the engine until 24h later to allow the RTV Sealant 24h to completely cure.

Congrats, you just fixed the most difficult problems of Oil Leak from "Freeze Plugs" faced by many BMW drivers for $12.00!

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#33 ·
I did mine a couple of weekends ago ('99 528it) and so far so good. Go ahead and take the time to replace your power steering hoses as well, and your belts if needed.

It is entirely possible to do this repair without removing the fan or shroud on an i6 car.

I also discovered that one of my hoses to my CCV had come loose, I had replaced it a couple of months back. Next stop, suspension work!
 
#35 ·
cn90, this DIY write up is great, I have recently completed changing the filter housing gasket of my M54 with no issue at all, took more than 3 days to complete the task & cleaning it but I am enjoying every bit of it as i have never done this before! FYI, i decided to install the rubber gasket without using any RTV gasket maker, torque to 24Nm (just to be sure)
Still have a few drop of oil this morning but as you advise it might be gone in a few weeks time as the area surrounding the filter housing looks clear, hopefully the oil pan gasket is fine.
 
#36 ·
cn09, this is a great tutorial, thank you.

This is my very first post, although I have been reading the forums for years. I have a 98 528, 5-speed, with 163K miles. I bought it new and have taken decent care of it. I have had very little non-routine maintenance issues (one wheel bearing, thermostat, and a gasket on the windshield wiper reservoir). I just started noticing some oil on the floor, and I think it is a result of the Oil Filter Housing Gasket, so I very much appreciate your help on this topic.

Out of curiosity, what other problems have you had to deal with on your car. It is my understanding that the Vanos seal issue, is not a problem on the 98's, only 99-2003....Is that correct?
Thanks.
 
#38 ·
How timely. My mother reported an awful smell from her 2000 528i, and our indy technician determined it was the oil filter gasket. She took it in yesterday, and for $450, got a new gasket, new filter, new alternator and A/C belts, new pully, and new breather hose. Apparently those are all located in the same area, so you might as well replace them.
 
#39 ·
Another Thanks to you for the help with this Oil Leak. My 2002 530i suddenly started using a quart of oil every 1000 to 1500 miles but I never have a leak in my garage or on the driveway. Had me stymied. I read this thread and searched the area in my engine.
This is it. I have it apart right now and I am doing all the Cooling system maintenance at the same time. FYI, the 2002 530i engine oil filter housing has threaded screw in plugs and not the press in freeze plugs. One less worry. My oil housing gasket was cooked and rock hard at only 75,000 miles.
Glad to find this leak. I am replacing the oil filter O rings also. This car has always had a rattle on start up. When I opened the Housing to remove the oil filter after this car had been sitting in my garage for several days the Oil filter was dry, no stored oil. I saw the oil drainback valve in the housing but I don't know if that is the cause of the oil drain back or if it is the two small O Rings at the base of the Housing Top below the filter. The 2 small O rings were rock hard when I removed them so I am pretty sure they were not sealing. It seems to me these two O rings should be replaced with every Oil change. Again these are the two small approx. 3/8" O rings not the large 3" O ring on the screw in top. Thanks again for the tips, they saved a lot of time.
 
#40 · (Edited)
...Glad to find this leak. I am replacing the oil filter O rings also. This car has always had a rattle on start up. When I opened the Housing to remove the oil filter after this car had been sitting in my garage for several days the Oil filter was dry, no stored oil. I saw the oil drainback valve in the housing but I don't know if that is the cause of the oil drain back or if it is the two small O Rings at the base of the Housing Top below the filter. The 2 small O rings were rock hard when I removed them so I am pretty sure they were not sealing. It seems to me these two O rings should be replaced with every Oil change. Again these are the two small approx. 3/8" O rings not the large 3" O ring on the screw in top. Thanks again for the tips, they saved a lot of time.
There are 2 ways oil can drain back down the sump:
- Via the 2 tiny O-rings during a typical oil change.
- Via the anti-drain device in the back of the OFH.

The 2 tiny O-rings on the Oil Filter Cap: Yes they prevent oil from draining down the sump. And that is their sole purpose during oil change.

The 1-way valve in the back of the OFH prevents oil from draining down the sump between engine starts.
One way to test your anti-drain valve (best to do this when oil is at Min level):
- If you can make a plugging device using the same tiny O-rings to plug the center hole, it'd be great.
- Remove the OFH Cap
- You will oil draining down via the center hole (where the 2 tiny O-rings block it)
- Plug the center hole and pour in 1/2 qt of oil. There should not be any drainage at all.
If there is drainage, then oil is draining down the sump.

---> At startup, do you have your engine oil pressure light flickering for 2-3 second?

Re: how often do you change the Tiny O-rings was discussed here.
Personally, I think these tiny O-rings should be changed every 30-40K miles.
At 90K, my oil filter housing Cap (the black plastic cap) cracked, so I got another cap from the dealer for $26 and of course the Tiny O-rings came with it.
http://www.bimmerfest.com/forums/showthread.php?t=411800
 
#41 ·
What are the torque values for the 6 bolts on the oil filter housing? I just did mine and I'm getting leaking. Since I did an oil change, the oil is very clean looking so I'm thinking I didn't torque the housing in very well and it is indeed leaking.
 
#42 ·
The Bolts are small so I think we are talking about inch pounds on this. I can look it up later and post. More important would be your method of torquing this housing. Bring all the bolts down evenly till all are touching the housing but no torque applied.
Look carefully to make sure your housing is evenly seated. Gap should be the same top and bottom and side to side. Bring it up very slowly turning bolts one at a time but limit to no more than one turn per bolt before moving on. Chris cross in a pattern to slowly bring this up tight.
If you tighten one bolt before moving on to the next you risk breaking the housing due to binding or your gasket can squease out and your chance of getting zero leaks is very low. I would follow the following pattern but I have not yet checked my manual.

1 3
6 5
4 2
Using a pattern like this should bring it down evenly and avoid Stress on the Oil Filter Housing. Again I stress, bring it up evenly or you will cause problems. If your eye see's one corner is out more than others stop and re address. You can always loosen the other bolts and start over.
Dirty threads can make you think a bolt is tightening when in reality you are just fighting the dirty threads. Always clean and Oil the threads to get uniform torque and the best result. If bolts are known to enter the water jacket substitute a thread sealer for the oil.
When it is down and evenly seated use your torque wrench to finish up. Even at the torque wrench application you are better off is you tighten in the pattern and do it in 3 steps. IF proper torque is 35 you can start with one lap at 15, one at 25 and the final torque to 35. This avoids stressing the aluminum housing and avoids the potential for breaking it or getting gasket leaks. This type gasket installs best clean with no silicone added. Use a very light coat of oil to help it slide and seat while you torque it. IF it sticks it will stretch and distort. These are very easy to install gaskets and pretty much a no brainer leak free seal until they get old and harden. The top left bolt has a dowel hole locating pin, I suspect you will need to work this bolt carefully as it will try and bind as you torque this housing. Again keep it even or you will fracture the housing. In years past I have made this mistake and had to pay for it. I hope you avoid it and get a trouble free, leak free installation.
 
#46 ·
Oil filter housing in parts cleaner?

What do you guys thing about putting the oil filter housing into a parts cleaner before reassembling it onto the engine? I'm talking about a regular automotive parts cleaner in a shop that you clean transmission cases in.
There isn't any parts that can be damaged from the heat is there?
 
#47 ·
What do you guys thing about putting the oil filter housing into a parts cleaner before reassembling it onto the engine? I'm talking about a regular automotive parts cleaner in a shop that you clean transmission cases in.
There isn't any parts that can be damaged from the heat is there?
The oil drainback valve would suffer and I could not see a way to take this apart and change it.

Mine cleaned right up with about 15 minutes of effort.
 
#48 ·
Oil leak on 2002 - 530i

Thank you for this valuable information I've been trying to find this oil leak for months and you pinpointed exactly. The gasket between the oil housing and engine block was shot very difficult to see until you remove the parts suggested. It would appear BMW changed the assembly slightly as I didnt have to repair the two casting plugs, they were already upgraded with two thread fittings. Ive also had to change the valve cover gasket and lower vanos valve which were also leaking in last year.
 
#49 · (Edited)
Hi

Dear all,

I found a noticeable information on this forum, so I decided to register myself, too.
I'm living in Switzerland, Europe and I drive a 1997 BMW 528i E39. Since I bought it I expected an oil leakage. I was twice to the BMW Garage, but they never fix it. Now with a friend of mine we're fixing it exactly like shown here. I hope that I can enjoy my car without any oil leakage in the future. My BMW has 320'000 km and the engine run very well after I fix the VANOS problem (I changed the O-Ring, the Camshaft & Crankshaft Sensor).

Thank you all for the helpful informations!

Coronet24
 
#50 ·
I started getting a vibration from the engine that I didn't get before I replaced the gasket. I know it's from the engine because revving it in neutral makes the vibration stronger and with high frequency.

I double checked to make sure I tightened all the bolts. The idler and tensioner pulley are brand new. The idler pulley is lined up properly.

Any ideas? I'm stumped.
 
#53 ·
Did my 99 last fall, it had the new type of screw in plugs. Doing my 97 right now and guess what?......... new type of plugs. Build date on the 97 is 6/96. I'm bowing the the Gods of BMW right now.


:thumbup:


I'm guessing that someone had the entire housing replaced a long time ago.


BTW, while you are down there and have the alternator out, PLEASE pull the plastic cover off the back of it and clean it out. Guaranteed to be a disgusting mess in there. Both of my cars had leaves and bugs clogging it. I hit it with degreaser, lightly scrubbed the entire alternator with a brush, then hit it with a spray bottle of warm water to rinse it, letting it dry, then I'll hit it with electronics cleaner spray. Don't forget to spray out the duct too. Probably a lot of mess in there as well.
 
#54 ·
For screw type plugs, what are you guys doing? I'm planning on doing this soon (got a leak coming down and I'm hoping it's not the wet hose coming from the sump). My idea is to use loctite silicone gasket maker on the exterior of the thing; without a hole to screw into (do I want to tap a Allen/Torx hole?) I'm not sure the washer will do anything additional.
 
#56 ·
Are you leaking from the plugs? If not, don't bother them. Just pull the housing and replace the gasket. Put some black RTV on the gasket between the housing and the block, and you should be set. I wouldn't try to tap those Torx holes, if you need to open them, get the appropriate sized Torx wrench and do it. You shouldn't be having any leaks from there now though. $5 says it's coming from the gasket.
 
#55 ·
No leakage until now

Hi guys,

since I've repaired the leakage with the washers, the screws and the high temperature silicone I've a clean engine and no more oil under it. :thumbup:

Actually my 528i has 344'000 km and the serviced VANOS system (Beisan O-Ring) works very well (more couple and less gear changes done by the automatic transmission). :thumbup:

Greetings from Switzerland,

Coronet24
 
#57 ·
CN90, you are my new hero. Great (again) DIY post. Weird thing with mine. Followed your instructions exactly and finished in under 2 hours. But dang thin kept leaking. Did it again. Still leaking. Drove 80 miles and no more leaks. Did the gasket just have to seat? Or perhaps I drove by an exorcism and picked up on the blessing. Anyway - great post and thanks!
 
#58 ·
Thank you CN90 for your detailed post. I have a question for everyone and that is do you simply "dry fit" the new gasket in or should I use some sort of grease, etc.? This is my 3rd E39 and first time doing this myself. I appreciate everyone's helpful thoughts and insights.
 
#59 ·
I'll be doing this repair in a couple of weeks when in my Christmas vacation. I plan to do it to my wife's e46 330xi first then my e39. I hope I can do both cars in the same day. There is not enough thanks to CN90 for writing this diy, he's a life saver.
 
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