Not the nose bearing, but it's somewhere close (leak)

[cowtown]

Hi, thanks for all the help with the RSR seals. Here's another question:

I rebuilt this '77 930 engine, including splitting the case, and in the 500 miles since, after shutdown it smokes from the nose bearing area - smoke comes out from between the motor mount plate (that covers the nose bearing/intermediate shaft cover area) and the case.

I pulled off the sheetmetal/turbo/motor mount and was sure I was going to see a Leland (nose bearing leak) but it's bone dry! Not even a film of oil anywhere in that area. The case halves are dry and the distributor is dry. I have not pulled of the i-shaft cover because I don't have a new gasket, but it looks dry too.

What's going on? I could swear the smoke rises from between that motor mount plate and the case...?

What else can I check around that area that would cause smoke? When running it's not noticible because the fan's spinning, but there is significant smoke when the engine is switched off for about 2-3 minutes.

Thanks for any help,
Colin

[john walker's workshop]

could the smoke be coming out of the fan instead? maybe that mouse on the head isn't done yet.

[cowtown]

Well, I pulled off the fan and didn't see any rodents, and it really seems like the smoke's coming from lower down. I am just baffled by this, because it all looks so clean. Im wondering if the turbo plumbing is leaking somewhere, and it just appears to be coming from that bearing area. The turbo tank's the only place that was a little grimy with oil.

Anyway, I was the happiest guy in CA yesterday when I found that is was NOT the bearing. I was sure I was in for another teardown.

[Tyson Schmidt]

Probably like you said, the heat from the turbo baking the grime on the turbo scavenge tank. Then the smoke is rising up through the area where you're seeing it.