[MadDog89]

What did it end up being, the oil pan or rear main seal? I read pretty much every thread on the topic and it seems that it's hard to tell if the leak is OPG or RMS or both.

I am also finding conflicting info, some say RMS leak is common on the n54 other say it's not. Then there are people who say that RMS pops out and leaks due to too much crankcase pressure as a result of higher boost and shitty PCV system.

[infinite_creations25]

mine ended up being the oil pan gasket. Everything is completely dry after replacement and this is at 100k miles

[Smgs1992]

Mine was my rear main seal. Shop replaced it when they did my clutch. They said my oil pan gasket looked fine for now.

[MadDog89]

Ordered one of those snake cameras. Crossing my fingers it's not the main seal, although if it is I'll probably take it somewhere to get it done. If it's the oil pan gasket, I'll do it myself and replace my turbos while I have my subframe down.

[stewbets]

It was both on my car 😂

I changed the oil pan gasket first and it slowed it down for a while, but then the RMS started leaking pretty bad. Mine was almost completely pushed out. I was able to pull it out by hand.

[mweisdorfer]

Originally Posted by MadDog89

What did it end up being, the oil pan or rear main seal? I read pretty much every thread on the topic and it seems that it's hard to tell if the leak is OPG or RMS or both.

I am also finding conflicting info, some say RMS leak is common on the n54 other say it's not. Then there are people who say that RMS pops out and leaks due to too much crankcase pressure as a result of higher boost and shitty PCV system.

One thing is for sure, they will both leak at some point in time, probably before 125,000 miles.

So, from a pragmatist stand point change the oil pan gasket first. Sandwich the OEM gasket in-between two beads of Ultra Black. If you still have a leak, then it's the RMS. Use the Ultra Grey for that one.

Do not use the BMW crap in the syringe that doesn't have a needle or plunger. Even if you do buy the needle & plunger, good luck getting the sealant out w/ out breaking the plunger & your fingers!

Again, at some point you will have to change both, so it's not wasted time & $$.

[Jeef]

you can use the rear main seal that doesn't require sealant too!

[lukemcmullen45]

Mine was the oil pan gasket.

[lukemcmullen45]

Oil pan gasket is much more common than the rear main seal on these cars, so Id be pretty certain it’s that

[TheN45Struggle]

Both....

[mweisdorfer]

Originally Posted by Jeef

you can use the rear main seal that doesn't require sealant too!

I wouldn't go that route. That's an awful lot of work to put a gasket only to find out that you now have to go back in and redo it ! 😉

[mweisdorfer]

Rear main seals, on an e90, are by no means rare. At some point between 90 & 150,000 miles the RMS will go!

It just that oil pan gaskets are more common. In that same breath, I'd say that between 90 & 150,000 miles the OPG will go! I think the OPG tends to go first is all... 🤔

[MadDog89]

Cleaned off all the oil around OPG and gave the florescent dye a go. I definitely see oil almost all the way around the pan, more toward the rear than the front. There is oil seeping past what appears to be rubber gasket. I also got one of those snake cameras and checked inside the access hole, did not see any oil or anything really.

I think it's more than likely my OPG. If I am going to replace it I might as well replace/upgrade my turbos and water pump while I have the subframe down. Will probably need to spend $2000 to buy all the stuff

[lukemcmullen45]

Originally Posted by MadDog89

Cleaned off all the oil around OPG and gave the florescent dye a go. I definitely see oil almost all the way around the pan, more toward the rear than the front. There is oil seeping past what appears to be rubber gasket. I also got one of those snake cameras and checked inside the access hole, did not see any oil or anything really.

I think it's more than likely my OPG. If I am going to replace it I might as well replace/upgrade my turbos and water pump while I have the subframe down. Will probably need to spend $2000 to buy all the stuff

Yea definitely sounds like oil pan gasket. And turbos probably isn’t necessary but will definitely save money in the long run, so have fun with that🤣

[nissubaru]

Originally Posted by mweisdorfer

I wouldn't go that route. That's an awful lot of work to put a gasket only to find out that you now have to go back in and redo it ! ��

From the looks of it the earlier years require a BMW sealant but the later years, I wanna say 09 and up don't require sealant. I did my RMS during the motor replacement and the sealant was not part of the TIS for my year.

Here are the newtis links supporting my statement.

Pre-09: https://www.newtis.info/tisv2/a/en/e...covers/HdGh1eS
N54s from 01/09: https://www.newtis.info/tisv2/a/en/e...overs/HEeL085t

[MadDog89]

Could a bad valve cover cause oil to leak from the pan due to excess crankcase pressure?

Planning to replace my valve cover first to rule that out, I'd image a crappy PCV would cause oil to seep past the OPG or maybe even the RMS.

[lukemcmullen45]

Originally Posted by MadDog89

Could a bad valve cover cause oil to leak from the pan due to excess crankcase pressure?

Planning to replace my valve cover first to rule that out, I'd image a crappy PCV would cause oil to seep past the OPG or maybe even the RMS.

Definitely go with an upgraded PCV Valve, also Id highly recommend an OCC if you’re going to upgrade the PCV system. If your oil pan gasket is already leaking then your going to have to replace it. It really sounds to be like Oil Pan Gasket, but if you want to replace the Valve Cover also, you might as well because you’ll have to eventually.

So try that first like you said, and if you want to you could try some Liqui Moly 2020, it’ll help with the leak for the mean time. I do it every oil change cause these cars just burn oil so much, even with PCV Valve and OCC.

[mweisdorfer]

Originally Posted by MadDog89

Could a bad valve cover cause oil to leak from the pan due to excess crankcase pressure?

Planning to replace my valve cover first to rule that out, I'd image a crappy PCV would cause oil to seep past the OPG or maybe even the RMS.

A bad PCV valve & crank case valve & hose can cause excessive pressure in the system & lead to a RMS, VC leak.

[cortez08]

Oil pan gasket at 65k and now rms at 86k. Rms is leaking badly and will be addressed during my next clutch swap coming soon.

[MadDog89]

Originally Posted by lukemcmullen45

Definitely go with an upgraded PCV Valve, also Id highly recommend an OCC if you’re going to upgrade the PCV system. If your oil pan gasket is already leaking then your going to have to replace it. It really sounds to be like Oil Pan Gasket, but if you want to replace the Valve Cover also, you might as well because you’ll have to eventually.

So try that first like you said, and if you want to you could try some Liqui Moly 2020, it’ll help with the leak for the mean time. I do it every oil change cause these cars just burn oil so much, even with PCV Valve and OCC.

already upgraded the PCV valve and got a new vent hose. Valve cover is original although the gasket has been replaced by previous owner about 2 years ago.

Originally Posted by mweisdorfer

A bad PCV valve & crank case valve & hose can cause excessive pressure in the system & lead to a RMS, VC leak.

If that is the case, then if I don't address the PCV system first and fix the OPG, RMS will go next. I keep seeing threads where guys fixed all the leaks and their RMS started leaking shortly after. My theory is that once you fix all the leaks top and bottom with bad PCV system then preassure will take the least path of resistance and pop goes the RMS.