It'* either bad vent, or those two seals in the rotor plate (not really user-replacable).

Assuming the leak only happens under boost.

If it drips all the time, even after a day or two of not driving, it'* gotta be the vent.

After driving home tonight, I looked really close at the breather bolt. The whole bolt is wet with SC oil and I can actually see very tiny air bubbles blowing out of the pourous center of the bolt. Somehow, there is pressure building up in the snout. How could that be possible if the belt is off the SC?

I don't see how the breather bolt could be bad. Its not a valve, its just a pourous piece of metal.

Could running without the SC belt be causing extra heat buildup, which is causig the pressure build up in the snout?

I'm so confused. . . . .

This past weekend I got around to replacing my SC coupler. Now that I have the SC belt back on, the leak appears to have stopped.

The only thing I can figure is that when you run with the belt off, extra heat builds up and increases the pressure in the snout, causing oil to be forced out of the breather bolt. OR when you run with the belt off, the seals do not stay seated, which allows oil to seep by.

I have always thought that is was OK to run without the SC belt, but this tells me that maybe it is not OK.

Why would you want to run without it? Performance and fuel mileage will both be drastically reduced.

In my case, my coupler was making so much noise that I took it off to save my sanity. Others have asked if it is OK to run without because their belt broke or a pulley went bad.

You are right, there would be no reason to run without the belt, unless there was a mechanical reason to do so.

I also had SC oil leaking out of my vent hole, even though it was plugged with the plastic plug. It'* not oil tight.

In fact, with the SC off, I was playing with it and tipping it so the snout was straight down. Duhhh, stinky oil leaked out all over my hand.

There'* a pic (and some ***-chewing) in this topic:

http://www.bonnevilleclub.com/forum/...ic.php?t=67586

That accurately reflects what we're talking about. There'* not much oil that makes it to the outer bearing. The seal doesn't really NEED to be oil-tight, as any oil that would make it out to the input shaft would only (typically) be from over-filling or leaky rotor seals.

Interesting topic. I've learned a bit in this one, as the M62 doesn't have the vent.

Well, although my leak has stopped, my noise has not. I changd out the coupler but the noise only got a little better. I just drove 250 miles on a business trip and it is now really loud. I will start another post with this problem, since it is a little different topic.

http://www.bonnevilleclub.com/forum/...ic.php?t=67637