Leaking mystery

[ziepro]

Keep noticing a buildup of an oily film on the right side of the engine/tranny area (where they mate) on my 01 R1100R.
The color of the film is similar to varnished gasoline, but it does not smell like it.
I cleaned it all off once and it came back slowly. Do I have a leaking seal?

[bmwmick]

That is not where a rear main seal leak would appear. That joint is the transmission front cover to transmission body. There is no seal or gasket there, it is assembled with RTV (loctite 518?) sealant.
It should smell like gear lube.

[screwtop]

I know you said it did not smell like gas, but I had that color staining on my GS in exactly the same spot and it was due to a small hose clamp leaking gas just above the throttle body. I tightened the clamp up and it went away.

[Motorcyclist]

I know you said it did not smell like gas, but I had that color staining on my GS in exactly the same spot and it was due to a small hose clamp leaking gas just above the throttle body. I tightened the clamp up and it went away.


+1 that looks like a gas stain. Check your clamps and quick disconnects.

[barryg]

Check your gas vent lines, example vent lines running to the charcoal chanister, over time they will deteriorate/dryrot. I had the same stain on my 94 R1100RS, I went to tighten up the hose clamps and found the lines crumbling away and causing the leakage and stain. I trimmed mine back a couple of inches and reattached for a quick fix, but will replace all the gas lines pretty soon for a long term fix.

[ziepro]

Thanks for looking at the photo and replying. Went home last night and found both clamps to the gas lines were loose (but rubber was intact!) and were the source of the leak.