common oil leaks

[E36dannym3]

was wondering common oil leaks on the 96 m3 i'm finding oil drips after driving only not just when parked

[shogun]

maybe you tell us a bit more in detail, such as oil color (black, red...), and in which area of the car, such as engine bay front, rear, right left, rear axle etc

Common is power steering fluid leak, front of engine at the bottom, the ATF fluid cooler line.

[chucktea]

Valve cover gasket. Mine was leaking in multiple places onto the ground as well as into cylinder #4.

[typed by ben]

Valve cover gasket, oil filter housing, oil filter housing machine port orings, power steering lines/reservoir, rear main seal, gear selector shaft seal.....

[TostitoBandito]

For engine oil, valve cover gasket, oil filter housing, dipstick (where it goes into the pan), and oil pan gasket.

Could also be ATF fluid from your power steering reservoir or one of the hoses, or could be transmission fluid from the gear selector or shaft seals.

[shogun]

today I was searching for a small leak under my M3, in the garage I always found some drops of oil coming out on the left side of plastic the belly pan. Power steering pump was oily, trans cooler lines in that area were oily, but that all did not fit/match to the color of the drops under the car = no ATF, no power steering fluid. So I checked more and found the troublemaker almost on top of the engine in front, the complete engine oil filter housing was oilyoutside, small leak from the oil filter cover O-ring 91X4 11421741000. Cleaned it up, tightened the oil filter cover bolt and will check, otherwise a will install a new o-ring.

[blckstrm]

today I was searching for a small leak under my M3, in the garage I always found some drops of oil coming out on the left side of plastic the belly pan. Power steering pump was oily, trans cooler lines in that area were oily, but that all did not fit/match to the color of the drops under the car = no ATF, no power steering fluid. So I checked more and found the troublemaker almost on top of the engine in front, the complete engine oil filter housing was oilyoutside, small leak from the oil filter cover O-ring 91X4 11421741000. Cleaned it up, tightened the oil filter cover bolt and will check, otherwise a will install a new o-ring.

I've had filter o-rings leak sometimes. Usually a couple extra pounds of torque stops it. One time that didn't work, so I loosened it, rotated it, and then torqued it again.

I just chalk it up to quality control on the o-rings.

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I've had everything mentioned in this thread leak on my car over the years. By far the worst / most frequent culprit is the power steering system.

[Hova]

I've had filter o-rings leak sometimes. Usually a couple extra pounds of torque stops it. One time that didn't work, so I loosened it, rotated it, and then torqued it again.

I just chalk it up to quality control on the o-rings.

Hmmm.. Could it be oil filter housing is out of spec? Are you using the copper o-ring under the screw on top of the cap?

https://www.realoem.com/bmw/enUS/sho...diagId=11_1288

#6.

Also I find that certain brands of oil filters fit differently. Are you using a Mann filter? Mahle? Try a different brand.

[blckstrm]

Hmmm.. Could it be oil filter housing is out of spec? Are you using the copper o-ring under the screw on top of the cap?

https://www.realoem.com/bmw/enUS/sho...diagId=11_1288

#6.

Also I find that certain brands of oil filters fit differently. Are you using a Mann filter? Mahle? Try a different brand.

All good questions. And yeah, I've noticed some are too tall and need to be crushed, which is troublesome.

Of course I always use all the new hardware - no sense reusing a crush washer or o-ring when you have a new one in the package.

I've started using Mann filters only and haven't had that problem for a long time, so like I said, it was probably just a quality issue with cheaper filters.

[shogun]

for reference 11427833769 BMW filter =
Mann Oil Filter Element - HU926/4x - E36 M3 S50/52, E46 M3 S54, complete oil filter kit = filter, large o-ring 91x4mm 11421741000 for filter housing cover, small o-ring for bolt seal, flat washer for bolt, and copper seal ring for the drain bolt.
Mahle OX 187D Contains: (Qty.) (1) Filter Cartridge, (1) Filter Housing Seal, (1) Metal Upper Screw Washer, (1) Lower Screw O-Ring, (1) Copper Drain Plug Seal.

Edit: I found the problem. Installed was a original BMW filter from Bosch with BMW part number and logo. The original O-Ring 91x4mm was a bit too large, actually 93.8mm inner dia., out of tolerance or bad production. Installed a new oil filter, that o-ring was fitting much better and tight on the lid, made a test drive, no more leaks.

[shogun]

Common BMW E36 Oil Leak Sources and Diagnosis https://abetterbmw.com/common-bmw-e3...and-diagnosis/
https://www.youtube.com/watch?v=4ZdjITxuaXE

[das borgen]

So many leaks. I just replaced my oil filter housing gasket and I still have a seeping leak somewhere I just can't find. Also, I just replaced my valve cover gasket and it's still leaking.

Has anyone found that the 92-95 magnesium valve cover gets bad with age and can develop leaks that aren't fixable with a new valve cover gasket?

[LockDots]

So many leaks. I just replaced my oil filter housing gasket and I still have a seeping leak somewhere I just can't find. Also, I just replaced my valve cover gasket and it's still leaking.

Has anyone found that the 92-95 magnesium valve cover gets bad with age and can develop leaks that aren't fixable with a new valve cover gasket?

Did you reuse the rubber grommets? You should have got new ones if you got a kit. Also, for oil leaks around the filter...if you haven't already changed it, you likely need a new oil filter housing gasket. Easy to replace (but a little messy) and it's definitely due for it given the car's age. Mine was almost solid and it basically crumbled when I got it out of the block.

[das borgen]

Did you reuse the rubber grommets? You should have got new ones if you got a kit. Also, for oil leaks around the filter...if you haven't already changed it, you likely need a new oil filter housing gasket. Easy to replace (but a little messy) and it's definitely due for it given the car's age. Mine was almost solid and it basically crumbled when I got it out of the block.

yes, I did replace those grommets.

As for the oil filter housing gasket, refer back to my original comment

[LockDots]

Doh! Don't know how I missed that. Carry on...

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[LockDots]

Might be time to get a few cans of brake cleaner and hit the engine everywhere you see oil to start being able to trace it when it leaks again.

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[das borgen]

Might be time to get a few cans of brake cleaner and hit the engine everywhere you see oil to start being able to trace it when it leaks again.

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I tried that, but that hasn't helped all too much

[h82crash]

Has anyone found that the 92-95 magnesium valve cover gets bad with age and can develop leaks that aren't fixable with a new valve cover gasket?

The mag covers are highly susceptible to corrosion. The corrosion is streaky and uneven and reminds me of old snow melt. Maybe you have some pinholes forming.