Fixing the oil filter housing leak at plugs on back side

[pment]

I have a 328is that I fixed this leak on and someone with an e39 requested that I post this here for those of you with a 528.

The oil filter housing you probably have has 2 pressed in plugs on the back side that may be leaking oil. Removing and reinstalling the oil filter housing is pretty easy. But you will have to thread the small round holes that are already in those pressed in plugs to enable you to remove them. Since they are aluminum, it isn't too hard to thread. You may need to use a bottom tap though. You only need a couple threads. I used a small slide hammer that threaded into the hole. The plug isn't in extremely tight. There is not an o-ring behind the plug in mine, but I have seen posts where it is claimed that some have o-rings. I believe there are only o-rings in the later model oil filter housings that also have plugs that screw in and don't require this procedure to get the plugs out. After removing the plug, clean up the hole and plug and use high temp Loctite when you lightly hammer it back into the hole.

As I said before, I think later models have a revised oil filter housing with these plugs threaded and use o-rings for the seal. I think any new oil filter housing you buy will come with this revised style of plug.

However, maybe you will want to fix your oil filter housing instead of buying a new one.

[cnn]

Thanks pment.

Does the inside look like this (with grooves) or smooth so I can tap a few threads in?




Here is my thread for 528i:
http://www.bimmerfest.com/forums/sho....php?p=4666825

Anyone who has done this fix, please post your solutions!

[Poolman]

I got the same leak--will be tackling this tomorrow. Should I remove the fan shroud to get at all this or just work around it? Thinking about just cleaning it up well and JB Weilding it sealed---The cars leaking enough now that there's a spot or two where I park her--and I have the gasket for replacement--I've read the DIY just wondering about the easy way to get this done--don't mind removing the shroud--once you have done that a few times --ya don't really fret over it anymore.

[newton22]

I think I have a housing gasket leak, but now it makes wonder if it's the plugs.

[Lance White]

I think I have a housing gasket leak, but now it makes wonder if it's the plugs.

The housing gasket is a very common leak in six cylinders - we do at least one a week in our shop. It suffers the same problem as the valve cover gasket - rectangular section gasket hardens and shrinks due to engine heat and oil. If you are that deep in the engine compartment, fix your other problems you might have or might soon have - tensioners, water pump and thermostat, power steering hose and reservoir leaks.

[cnn]

,,,,,,The cars leaking enough now that there's a spot or two where I park her--and I have the gasket for replacement--I've read the DIY just wondering about the easy way to get this done--don't mind removing the shroud--once you have done that a few times --ya don't really fret over it anymore.

Poolman,

Don't touch it yet. I am working on a permament solution using Aluminum Plug like this:


It is harder than you think but I am positive I found solution, I am waiting for the Aluminum Plug to arrive in the mail (ordered through ebay).

I will do a DIY very soon, so stay tuned!

cnn
(aka cn90 on bimmerfest!)

PS: Lance White, we are talking about the two (2) Freeze Plugs in the back of the Oil Housing. Not the gasket which is easy to replace.
The two (2) Freeze Plugs are a challenge to fix.

[Poolman]

I'm in no hurry CN90--will wait and see what ya have for the fix---I'm still pulling full vacuum in my crankcase and the oil useage is completly stoped as in my previous threads on that problem--was going to hook up a new ccv system while making the fix on the oil leak ---been a month or so with the set up not using the ccv---running it this way is giving me a code which reads that the engine is running too rich on both Banks--1 and 2. I can do it all later--it'll just be a little colder when I dig into to it.

[pment]

Nope. My plugs had a counterbore where yours has a boss sticking out. Also there is no groove for a retaining ring in the hole the plug resides in.

Thanks pment.

Does the inside look like this (with grooves) or smooth so I can tap a few threads in?




Here is my thread for 528i:
http://www.bimmerfest.com/forums/sho....php?p=4666825

Anyone who has done this fix, please post your solutions!

[cnn]

Nope. My plugs had a counterbore....

Thanks! Couple of quick questions:

1. Do you remember the Tap Drill Bit Size to make new NPT Threads for the new plug?

2. I borrow this pic from wikipedia, so does yours look like this (similar to the Engine Welch Plug Counterbore)?

[pment]

My fix is completely different. First, the threads are tapped into the counterbore of the plug just so you can pull the plug out of the hole. Then I clean up the hole and the plug and put loctite on the plug and in the hole. I push the plug back into the hole and rely on the loctite to provide a leak free seal and to also hold the plug in the hole.

You must know that I have a 97 e36 and that someone asked me to post to this forum how I fixed my 328is. Maybe your housings aren't the same as mine.

[cnn]

My fix is completely different. First, the threads are tapped into the counterbore of the plug just so you can pull the plug out of the hole. Then I clean up the hole and the plug and put loctite on the plug and in the hole. I push the plug back into the hole and rely on the loctite to provide a leak free seal and to also hold the plug in the hole.

You must know that I have a 97 e36 and that someone asked me to post to this forum how I fixed my 328is. Maybe your housings aren't the same as mine.

Thanks! I know exactly what you are talking about.
If I remember correctly, then in another thread, you mentioned that you took the Housing to a machine shop to make the NPT thread for the plug for you.

- The NPT thread INFO is exactly what I need. If you have the NPT Thread info, then it is great.
- If not, no problem, I appreciate your help.

[pment]

That must have been someone else for the NPT tap.

I just had a machine shop place a thread in the counterbore of the plug so I could use a slide hammer to pull the plug out of the oil filter housing. I didn't thread the housing. I just used loctite on the plug and put it back in the hole of the oil filter housing. The loctite is the only thing holding the plug in the oil filter housing. After seeing them tap the plug, I realized that anyone could tap the thread in the aluminum plug.

[cnn]

Thanks pment,

Now I realized that someone else did the tapping for new threads. It is CJH in bimmerfest:
http://www.bimmerfest.com/forums/sho...t=cjh+oil+plug


Anyone has a used (Leaking Recessed Plugs is fine) M52 Oil Filter Housing laying around so I can use as a guinea pig? I will return it in repaired condition (if the guinea pig is still alive LOL)

Here is what I am getting at, for those familiar with NPT (National Pipe Thread Tapered Thread) concept, it is basically Tapered Thread for good sealing.

The 3/4" Blue Anodized NPT Plug I just received has the standard NPT dimensions:
- Inner Groove: 24.80 mm
- Outer Thread Tips: 26.67 mm

Therefore, on the O.F. Housing Side, the bore size must be around or less than < 24-25 mm, this way I have room to tap the threads.

Again, I NEED A GUINEA PIG please!

[pment]

If you want to use a 3/4 NPT pipe plug, the hole should be Ø23.4mm(59/64") or less.

Thanks pment,

Now I realized that someone else did the tapping for new threads. It is CJH in bimmerfest:
http://www.bimmerfest.com/forums/sho...t=cjh+oil+plug


Anyone has a used (Leaking Recessed Plugs is fine) M52 Oil Filter Housing laying around so I can use as a guinea pig? I will return it in repaired condition (if the guinea pig is still alive LOL)

Here is what I am getting at, for those familiar with NPT (National Pipe Thread Tapered Thread) concept, it is basically Tapered Thread for good sealing.

The 3/4" Blue Anodized NPT Plug I just received has the standard NPT dimensions:
- Inner Groove: 24.80 mm
- Outer Thread Tips: 26.67 mm

Therefore, on the O.F. Housing Side, the bore size must be around or less than < 24-25 mm, this way I have room to tap the threads.

Again, I NEED A GUINEA PIG please!

[cnn]

Just came up with another idea along the same line with EuroDavid's JBWeld idea:
http://bimmer.roadfly.com/bmw/forums/e39/9384566-1.html
But I am planning on using roofing asphalt caulk.

- Tap a proper bolt thread into the small recess (the ? 4mm recess in aluminum plug in your pic).

- Spread a thin layer of Roofing Black Asphalt Caulk similar to this:



- Then large washer (about 30-mm in diamter) to cover it.

- Gently put the bolt back on finger-tight and the fix should be permanent.

[cnn]

Update,

Using:
- M7 bolts threaded into the small hole of the "Freeze Plugs"
- Washers
- Asphalt Caulk
- Permatex RTV Gasket Maker.

It works, no longer leaks at the 2 "Freeze Plugs".

Detail info is here:
http://forums.bimmerforums.com/forum....php?t=1160904