Quote:
Originally Posted by cn90
The video below shows a very comprehensive review of ALL possible oil leak sources for M54 engine.
Pay attention to time marking 2:45 where the person discussed the RMS, note the particular bolt I mentioned in earlier threads? It is wet with oil in the video. So I am very convinced that the oil at that particular bolt is from a RMS leak. If you do the CCV Mod, then it keeps the leak down to a minimum.
https://www.youtube.com/watch?v=TyTL8wosXKo |
Great video. I'm not worried about it, but I think I've got a RMS leak on my 2001 M54B30. So far, it's nothing the stiffening plate can't handle.
When I rebuilt the top end last summer and had things pretty well stripped down, I inspected the oil pan seam for leaks and it seemed perfect. I tried putting some torque on each bolt (pretty low, they are M6, and I think the manual specifies 10 Nm if they are class 8.8 and 14 Nm if the bolts are marked class 10.9 [all this from memory, so look it up]) and nothing at all moved.
Looking at the video, e.g., the frame at 3:12 with a view of the back face of the engine, ...
https://youtu.be/TyTL8wosXKo?t=192
you can see the residual oil that is directly below the crankshaft at the engine-AT interface. With that view, and also seeing the oil on the lower part of the RMS, it seems clear that the oil is leaking past the RMS, then down into the cavity below, and finally leaking through the unsealed gap between the engine pan and the AT.
But without that view, it might not be clear whether it is the RMS or the oil pan gasket right below the RMS that is leaking. Both would exit at the same point below. So that's when you might (I do) figure that if the rest of the oil pan gasket is tight, the chances that it's leaking right below the RMS is not likely, and it's probably the RMS. So that's what I'm concluding for now.
BTW, I've also come across a case on this forum for the M54 where it was actually the AT front seal leaking, still exiting at that point, looking brown like engine oil vs. red like DEXRON VI (or III) as it exited. Disassembly confirmed it was the AT. Interesting.
And it makes perfect sense that the oil pan gasket, if it leaks, would leak in areas near the axle, with more stuff going on there to disturb things.