Silicone RTV for Oil Filter Housing Gasket?

[bmwman91]

So I have two days until I get the proper injectors and chip for my MM Rally 2100 motor. When I was talking to them on the phone friday, they recommended putting Permatex Ultra Grey RTV on both sides of the oil filter housing gasket because it will leak otherwise. I did so when I was assembling everything this weekend.

As I was cleaning up the garage this evening, it occurred to me that this could be dangerous. All gasketing surfaces were coated. I didn't go crazy with the stuff or anything, but some did squeeze out as I tightened the bolts. It obviously will squeeze out on the inside too, which is my concern. Some of those oil passages are "clean" ones for the oil that has been filtered, right? If some of the excess broke off and lodged at the outlet for a main bearing or something, I would really be screwed.

From looking around, it sounds like all sorts of people use silicone RTV on this gasket, on this motor and others with the same sort of housing (if all of your friends jump off of a cliff...). I really have no idea what passage is which in the housing though. Is it possible that all of the ports by the paper gasket are "dirty" ones, and the big round thing with the o-ring is for the clean/filtered oil?

The lower/gasketed portion looks to have 3 oil flow ports:
- The two square ports seem to be for the pressure bypass valve, so chunks of RTV wouldn't get into the motor that way.
- The upper port seems to be where oil feeds in from the pump.

- The round thing with the o-ring & some sort of valve in it is presumably for clean oil output? If that is the case then I guess I am not so worried since there isn't any RTV that will squeeze in there. I DID apply some to the timing case up around the hole for it, but I made sure that none was in the hole and I am 90% sure that I didn't push any in when I mated the housing to the timing case. That would be the only way that RTV could have gotten in there.

Dammit...maybe I should just pull the housing tomorrow to be sure? I would be so pissed if I ruined this motor with a sloppy mistake. Am I just worn out from 3 days of wrenching and being silly?

[bmwman91]

I spoke with Teddy at MM this morning. All of the stuff down where the paper gasket is has dirty / pre-filter oil going in it. So, if a chunk broke loose it would end up in the filter or in the cavity above the bypass valve which isn't a problem. As long as none got into the circular opening where the clean oil goes, it is all good.

I am not 100% sure that I didn't get some in the circular part, so I am pulling the housing this evening & re-doing it. At this point, peace of mind is worth an extra 1-2 hours of labor.

[bmwman91]

I pulled the oil filter housing to check everything this evening. I probably would have been fine since I didn't see any in the clean oil outlet, but I did goop way too much into the inlets. It would have ended up in the filter, probably. Anyway, I had a spare filter housing gasket handy so it was no big deal. I put some RTV onto my gloved finger and spread a thin layer onto the housing and timing case before assembly. And of course I made darn sure that no RTV was on the round outlet or o-ring, or in the round hole! That section is now good to go! Phew!

Since the injectors and chip don't come until tomorrow anyway, this works out well. The RTV will have had 24 hours to cure, which is just right!

[cristimm]

Good info.