DIY: Oil Leak Location Question

[BMWE46M3]

I've been having an oil leak at the same location for a while and just removed the bolt where the oil consistently leaks from. I've attached a photo of the bolt and location. Is this a bolt for the oil pan or something else? If you noticed when I removed the bolt it has oil all over it. I'm assuming the bolt should be dry. Any help would be appreciated. Thanks...

[Cubieman]

I've been having an oil leak at the same location for a while and just removed the bolt where the oil consistently leaks from. I've attached a photo of the bolt and location. Is this a bolt for the oil pan or something else? If you noticed when I removed the bolt it has oil all over it. I'm assuming the bolt should be dry. Any help would be appreciated. Thanks...

I would think oil pan gasket or rear main seal, but if it was a rear main seal leaking I would *assume* you would see oil leaking from those inspection holes on the transmission.

That bolt looks as though it could be part #11 on the realoem diagram and it lists a quantity of 2, so these longer bolts may be used on both corners in the rear corners of the oil pan.

[Chanman1029]

Thats an oil pan bolt, I suspect the inside of the gasket is torn, allowing oil to see into the bolt

[BMWE46M3]

Thanks guys, is there anything I can do about it? The oil pan gasket was recently replaced before I bought the car, and this is the only point that’s leaking.

[sapote]

I've been having an oil leak at the same location for a while and just removed the bolt where the oil consistently leaks from. I've attached a photo of the bolt and location. Is this a bolt for the oil pan or something else? If you noticed when I removed the bolt it has oil all over it. I'm assuming the bolt should be dry. Any help would be appreciated. Thanks...

This long bolt has the same function as the other 2 short bolts between the pan and the tranny, so it is rare that oil leaks down this bolt but not the 2 nearby short bolts.
Solution: drain the oil and remove this bolt, let oil in the long hole drip out overnight. Clean the section near the bolt head and washer really good, and the pan hole too. Should be zero oil residual in the hole and everything near the bolt head. thread the bolt until about 10mm remain before bolt head bottomed out, add black RTV on the bolt above and on the top side of washer -- RTV about 10mm high and diameter slightly larger than the pan hole, insert the bolt, then thread it and torque to spec. Let it dry 24 hrs. Fill oil and drive with no more oil leak.

[heinzboehmer]

add black RTV on the bolt above and on the top side of washer -- RTV about 10mm high and diameter slightly larger than the pan hole, insert the bolt, then thread it and torque to spec.

10mm of RTV?

Did you add an extra 0 in there lol

[sapote]

10mm of RTV?

Did you add an extra 0 in there lol

Yes, fill 10mm section between the bolt and the pan hole. As the bolt is turning, it needs this much of RTV to settle down and fill the gap. This is not just between washer and pan.

[Slideways]

How much oil are we talking about? This seems like a leave it as-is situation till the next time the oil pan needs to be removed (unless it is leaking from the rear main seal).

[BMWE46M3]

Thanks guys, I will try the RTV method and let you guys know how it works.

[BMWE46M3]

So I cleaned the bolt and cleaned the hole in the housing so the RTV would have a clean surface to bond with. I applied the RTV, finger tightened it as directed, then after an hour I go and tighten to spec and the damn bolt snaps! The fracture was in the treads. So there is no way for me to get the rest of the bolt out unless I remove the oil pan which I really don't want to do. So filled the hole up with more RTV and inserted the remaining part of the bolt into the hole and coated the head of the bolt and washer with RTV. I plan to let it dry for a couple days.

Do you guys think I'll be ok or will the oil pressure simply be too great resulting in a leak? Thanks...

[sapote]

So I cleaned the bolt and cleaned the hole in the housing so the RTV would have a clean surface to bond with. I applied the RTV, finger tightened it as directed, then after an hour I go and tighten to spec and the damn bolt snaps! The fracture was in the treads. So there is no way for me to get the rest of the bolt out unless I remove the oil pan which I really don't want to do. So filled the hole up with more RTV and inserted the remaining part of the bolt into the hole and coated the head of the bolt and washer with RTV. I plan to let it dry for a couple days.

Do you guys think I'll be ok or will the oil pressure simply be too great resulting in a leak? Thanks...

Sorry to hear the bolt broke. If the broken bolt has no threads on it then I don't insert it back in for no good reason. Clean off all the cured RTV from the hole, then fill the hole with fresh RTV about 10mm deep. For short term, the pan will be OK and hopefully no new oil leak, this should be fixed when you have the chance to drop the pan for rod or whatever work to be done.

"I applied the RTV, finger tightened it as directed, then after an hour I go and tighten to spec "
why did you wait for one hour to tighten the bolt? It should be tighten ASAP when the RTV is fresh, not cured as this resulted in a broken bond between the bolt and the pan hole.

How much was the bolt torqued to?

[BMWE46M3]

Thanks…

[Chanman1029]

Very unfortunate man, my condolences

[cobra]

Well have you done the rod bearings?

[heinzboehmer]

Maybe try a screw extractor? Can't imagine what remains of the bolt is torqued too tight