N62 2005 lower oil pan gasket still leaking

[X5only]

Replaced leaking lower oil pan steel gasket on my 2005 X5 with N62 4.4 engine with BMW dealer gasket per instructions of Newtis and Bentley manual (bolt tightening order and torque spec). Several months later, it started leaking again. But now noticed that real OEM lists Loctite 5970 Liquid Sealant as a required part for repairs of the gasket. However, when I'd removed the old steel gasket, there were no signs that a sealant was used from factory. Also, Newtis and Bentley manual do not mention this sealant. What is your experience? Did you use this sealant and if not, is the new gasket not leaking long-term?

[andrewwynn]

I've changed a couple m62 opg not n62 did not use sealant did not long term follow-up though.

That's crazy that newtis doesn't mention but realoem does.

My n55 opg been leaking since i bought it but the 13 hour 105 page procedure has me holding off.

I'll treat it with ATP AT-205 and the leak slows 80-90%. Lasts usually better part of a year. I've been wanting to change the rod bearings so then I'll finality get to the OPG of course.

Are you 100% certain not a higher up leak coming down to the lower seal? Did you clean the surface with scotch bright before reassemble and lastly, does your truck use the special zinc "microencapsulated" screws that are supposed to be replaced? (I don't think they stretch during assembly i think the coating gets damaged so they will weld to the aluminum pan, so should not have bearing on leak).

Any chance you had damage to the pan from a curb strike etc?

[BimmerBreaker]

I'm in the midst of rebuilding a 4.8 and observed this too when ordering parts for the rebuild. I didn't remember seeing that note last time I ordered that gasket so I checked TIS and there is no mention of it there as you've noted.

The x5 oil pan gasket is different than the RWD models. On the RWD ones there is a section where the rubber on the gasket doesn't like up with the sealing surfaces. The x5 steel one seems like it matches better but the rwd ones will *not* seal properly...

Some of the newer engines do not even use a traditional gasket. They seal with *just* the Loctite 5970. I am considering skipping the gasket on my lower oil pan and using just the 5970.

[BimmerBreaker]

Oil sumps are a different shape but process would be the same on the X5. Clean both mating surfaces thoroughly, apply a ~2mm bead of sealant, join the parts within 10 minutes and tighten

I won't know for a little bit whether or not it leaks but BMW uses this stuff in lieu of normal gaskets on their modern engine oil sumps, differential covers, even water pumps and some other areas. Seems to be pretty good stuff

[Factory6speed]

You should smear it with your finger so it doesn't glob.

The b58 uses that for the oil pan and timing cover. It's a pain to remove. Make sure it's not way expired (it's very hard to find a tube of the 5970 that is not expired!) and spread it with finger to get a nice even layer, remove the excess globs that could eventually find their way into your oil pickup

I don't know anything about the v8s but on the straight six when you do the oil pan you have to put the sealant in the four little corners where the front and rear covers meet the block. There are 3 90° angles meeting and a gasket on two of them isn't going to do it so you put sealant in those spots. I imagine the V8 would be about the same with the front and rear cover.

[BimmerBreaker]

I just installed it per recommended specifications - it does not say to smear it in any application instructions so I didn't.

N62 upper oil pan gasket has a sealant built in where it meets the front timing cover and rear main seal. I installed the rear main completely level with the block before oil pan was on and just used the upper oil pan gasket without additional sealant. This is what I did when I rebuilt the original 4.4 and there were zero leaks from this area.

[X5only]

Originally Posted by BimmerBreaker

I just installed it per recommended specifications - it does not say to smear it in any application instructions so I didn't.

N62 upper oil pan gasket has a sealant built in where it meets the front timing cover and rear main seal. I installed the rear main completely level with the block before oil pan was on and just used the upper oil pan gasket without additional sealant. This is what I did when I rebuilt the original 4.4 and there were zero leaks from this area.

My N62 lower oil pan did not leak but after approximately 3 months, it started leaking again. How long ago did you do the lower oil pan?

[BimmerBreaker]

I did the original 4.4 rebuild in 2021, a very small amount started leaking from the lower oil pan starting after a few months.

The area that did not leak was the upper oil pan gasket, where the person I replied to mentioned using RTV at specific locations, which is NOT necessary on the N62.

The Loctite sealant on the 4.8 rebuild I did yesterday. I have not had oil in it yet, I still need to finish the rest of the rebuild.

[X5only]

Yeah, it appears that the N62 engine lower oil pan will leak later if sealant (Loctite 5970 Liquid or an equivalent RTV) is not applied when installing a new steel gasket. I was very meticulous about the installation but was baffled when the lower oil pan gasket started leaking again after 3 or 4 months. The install is easy, so I'll do it again with sealant applied.

[BimmerBreaker]

The lower oil pan was not designed to use sealant, the original TIS instructions not mentioning sealant reflect this. The realoem note was added retroactively at some point. The gaskets were designed to do the sealing, the "ridge" in the steel X5 gasket and the integrated rubber strip on the RWD model gaskets were supposed to do the sealing. It just doesn't always work that well for whatever reason.

Also important to note that the Loctite 5970 sealant is used instead of a gasket, it was not designed to be used with gaskets. Every BMW application using this sealant does not use a gasket. I omitted the gasket completely on my most recent rebuild.

I've rebuilt quite a few BMW engines in my day and in most cases the stock gaskets work very well. I do not take the idea of replacing a gasket with sealant lightly and in fact this is the first time I've ever done so - but it does seem likely to be the best method in this instance.

Last little note - most RTV's available in store are acetoxy or oxime type sealants - not equivalent to the Loctite 5970 which is an alkoxy sealant. The cost difference is trivial enough for me not to even consider using a permatex type RTV in this application.