[motorwaycruiser]

Hello all, I am in the process of doing a major engine refresh on my 325ci that has almost 190k miles. I have disassembled the oil filter housing which was caked in a black oily carbon residue from some leak (probably the oil pan since that has keep dripping since lifting the car up). Nonetheless, after cleaning, I discovered some nicks on the mating surface of the housing. I read in another recent thread that an experienced member here suggested resurfacing the mating surface with emery cloth as warping will be inevitable. Is this necessary for my housing?

I have attached a couple pictures showing the nicks on the mating surface. Additionally, are the score marks where the gasket sits anything to worry about? I want to make sure this crucial component does not leak when I put it back together. Thank you

 

[TobyB]

I would ONLY 'nib' those off (you can use a razor blade) as the seal doen't seal there.

All you want to do is make sure they don't hold the housing proud of the block surface,
nothing more.

t
most things we do in garages make flat surfaces less flat.

 

[RayLivingston]

As long as the actual sealing surface is smooth, those little divots don't matter one bit.

If that is the original check valve, replace it. It almost certainly leaks.

 

[motorwaycruiser]

Wow quick responses! That's great news to hear. The rest of the sealing surface is quite smooth without any pitting or scrapes so I think that's good to go! Thanks for letting me know of the check valve. I shall be replacing it.

 

[VpointVick]

If you have a sharpening stone for knives it wouldn't hurt at all to swipe that over the surface until it runs smoothly.
I work in machine tool manufacturing (building CNC milling machines) and that's what we do to make sure that there are no high spots when assembling mating surfaces.

 

[DEADF15H]

For truing up the flatness of a hand plane used in woodworking, we lay down a piece of plate glass and spray mount a piece of sand paper to it. It can take a while, depending on the grade of sandpaper, but planes and blades need to be polished perfectly flat.
I do like the idea of a sharpening stone, why my method can't be used due to location of the surface.
Just make sure you clean thoroughly when done.


Sent from my SM-N960U using Tapatalk

 

[jdstrickland]

I like the idea of a whetstone (wet stone?) to polish the edge. Just burnish off the defects that can make contact with the mating surface.

 

[Bike Rider]

I saw similar when I removed the ATF pan. I polished it smooth with scotch brute, wire wool and Emery paper. No leaking at all.

 

[MrMCar]

Those are from a sideways pry with a tool in an effort to remove seal material from the valleys.
Be it you or the last person to do the job.

Those areas are raised. I would sand it on a surface plate if it were my car. Those spots are higher.

 

[MrMCar]

This thread and in particular post # 142:

Touring rebuild with interior swap

I picked up a piece of granite from a local stone guy. Off cut from a job. I got emery cloth (220) from Harbor Freight. questions: 1. Do I use any spray adhesive to keep the emery cloth from slipping? 2. Wet or dry? I do such dry.

www.e46fanatics.com

 

[BigBopper]

Hello all, I am in the process of doing a major engine refresh on my 325ci that has almost 190k miles. I have disassembled the oil filter housing which was caked in a black oily carbon residue from some leak (probably the oil pan since that has keep dripping since lifting the car up). Nonetheless, after cleaning, I discovered some nicks on the mating surface of the housing. I read in another recent thread that an experienced member here suggested resurfacing the mating surface with emery cloth as warping will be inevitable. Is this necessary for my housing?

I have attached a couple pictures showing the nicks on the mating surface. Additionally, are the score marks where the gasket sits anything to worry about? I want to make sure this crucial component does not leak when I put it back together. Thank you

View attachment 929774

View attachment 929775

Not a problem. Just make sure you clean that gasket groove out thoroughly. I can see some residue in there. And tighten up the top 4 bolts first in a criss cross fashion. Then do the bottom two.

 

[motorwaycruiser]

Thanks all for the advice! It seems the best way to go about it is lightly flatten the bump. I'll try and use a small strip of emery cloth to rub it down as flush as possible.

 

[VpointVick]

Thanks all for the advice! It seems the best way to go about it is lightly flatten the bump. I'll try and use a small strip of emery cloth to rub it down as flush as possible.

Be careful not to make low spots.
We use whet stones since they're flat and will flatten the surface evenly.

 

[MrMCar]

You want to use a WHOLE sheet.
The idea is to lightly sand the ENTIRE mating surface at one time. This way it sits FLAT when bolted down.
Working only one area would lead to a untrue surface and future leaks.

 

[motorwaycruiser]

Thanks everyone for the insight. I did some research into the check valve and it looks like there's no real simple way to replace that part. There's a a metal replacement check valve from Russia, but the process of replacing it seems more of a hassle than it's worth. I ended up ordering a new oil filter housing since it was on sale. My goal is to drive the wheels off this high mileage 325 so I felt it was worth it to simply get a new housing.