Strange Oil leak GS1150 from Engine Ventilation???

[earlfor]

Ryan
If the hole vents the ignition case to outside air, then what is the point in this?
The ignition sensors do not require venting and there is no oil flow through the ignition case either. (I understand the oil is not coming from the ignition)
I can understand why a vent would be on the underside rather than the top because of rain, by why at all?

Earl

half of the hole has connection to the area behind the ignition cover and the other half has connection to the outside air where your seeing the leak. I would think the oil is coming from between the upper and lower portion of the cases. There is no gasket just some case sealer smeared between the two halves. I can email you a pic of what it looks like with the cases split if you want.

[kz]

Karl if you dont find a problem with the breather on the camcover I suggest that you re-torque the cases, that is what fixed it on my 1150.
Dink

Dink:

Did you also have a problem with oil comming out of that hole on your GS 1150 or ws it leaking between the cases in general?

Was the problem fixed just by retourqing the cases?

Inside the ignition cover I could see some small amount of oil, but it looked more like the oil has got in from that hole rather poored than out.

[Dink]

IT seemed to be coming from that area Karl I spoke to the Mechanics where I work and their suggestion was to re-torque the cases , and it worked .
Dink

[rosco15]

Clean it up really good and make sure it isn't coming from the rubber gasket the crank spins in. When I blew the base gasket on my bike I coulda sworn it was coming from the front where the cases join together. I cleaned it all up and found where it was really coming from.

[kz]

OK,
I have dismantled the blow-by/oil-trap assembly on the top of the valve cover.

It looks like:

http://medlem.spray.se/ocorsagsi/PICT0469.JPG

http://medlem.spray.se/ocorsagsi/PICT0477.JPG

First I removed the hose at the Air-cleaner side and could almost not feal any pressure, then I started the engine again without blow-by/oil-trap assembly, couldn't feel much pressure then either and no oil was splashing around. (At 2500 rpm, cold engine)

I removed the oil filler cup and started the engine, there was a pulsating pressure, and no oil was coming up through the oil filler hole as the engine ran.

I checked the oil level and it is OK.

How big should the difference between the pressure at the oil filler cup and the open hose (with mounted oil-filler cup)?

Now it was a big difference in pressure.

Could something has been wrong mounted or blocked in the rest of the valve cover assembly?

Dink:

I just tested the front casing bolts and they where not lose, I haven't re-torqued yet.

Ryan:

How could I see if the rubber gasket is leaking? Any hints?

[rosco15]

You have mail. I dont have a clue what the hole is for.

[oldschoolGS]

You could have a high pressure problem. I do not know how much higher the 750 pump pushes the oil in your motor, but at those temps (-6C to 5C) 20-50 oil is too thick to use. Using an oil temp chart , 20-50 should only be used when ambient air temps consistently get above about 25C (80F). Any lower than this and 10-40 is recomended. While the difference between 10-40 and 20-50 is not that great, this combined with any extra psi delivered by the 750 pump could cause excessive oil pressure to vent. Good Luck, Ed.

[earlfor]

Karl, I still believe the hole is a auxillary pressure relief for the crankcase.
that is the only purpose that makes sense to me. Have you ridden the bike long enough to warm it up to normal operating temperature, then stopped and wiped off the oil drip and continued riding to see if it still drips after the oil is hot and thinned?

Earl

[Anonymous]

20w50 says it can be used down to -10C but I think that's if you give it lots of time to warm up. Have you run it at this low of a temp before? At -20 that grade oil turns into toffee so I can picture your engine litterally pumping the valve cover full of thick oil thus leaving the oil level really low. That doesn't address your leaking problem but it's something to think about.

As for the breather gasket, you shouldn't be able to get it backwards as long as when you sit it on the engine you can see the passageway through the holes. I made one for my 400 a few years ago and my only problem with it is that the tube and valve cover area fills up with an oil/water sludge.

Steve

[kz]

Hi,

A new Day and new tests?

I checked the pictures Ryan sent to me and studied the hole design on the engine as well.

The hole has only connection to the area behind the ignition cover and not to the crankcase.

In my opinion the hole must be a drain hole for the area behind the ignition cover; this also makes sense, because there is no gasket for the ignition cover.

The oil is not leaking out from the ignition area; I tested by putting paper on top of the hole behind the ignition cover.

The leak can only be between the cases, the oil travels between the cases and comes out through the drain hole.

My question now is what caused it?

Is leaking between the cases a normal problem?

Is it possible to glue?

Of course I will try to re-torque the case first...

The Blow-by issue:

After the engine gets warm the pressure at the valve cover hose increases, but is still much higher at the oil filler cup.

Earl:

Yes I have been driven the bike at normal engine temp, up to 100 C; if the engine is cold it leaks less than if its warm.

If I drive at low RPM it leaks less, almost nothing, it starts to leak after 6000 rpm and more.

[Anonymous]

The hole has to be for pressure relief. But it's kind of a weird design thing. When the cover is on that is a closed cavitiy, but it doesn't contain anything :? . From what I can see the only way for oil to get to that area is through where the cases split. Oil really couldn't get in there from the where the ignition pickup is, it's really two seperate areas when the cover is on. I think Dink has the best idea, retorque the case.

FYI - the 1100 cases have the same setup.
KZ,
My 1100 cases are apart (still) so if want a pic of how it looks apart let me know.

[kz]

Hi again,

Re-torqued today, no change in leaking.

Tested the to "de-pressurize" the crankcase by removing the oil-filler cup and installing a hose instead, drove like this for approx. 15 km.

The pressure in the crankcase looks not to have any influence on the leak.

So finally I put a little super-glue on the edge inside the hole gluing the cases toghether, only a tiny spot of approx. 5 mm. :twisted: :twisted:

The draining/venting is still open and works as it should.

Have been driving for approx 40 km now and NO MORE LEAK!

Hopefully it doesn?t come back. :roll:

Thanks all for your help.

[earlfor]

That makes perfect sense karl. If the hole is not connected to the crankcase oil, then it cannot be a pressure relief vent. The ignition has no need for a vent, but without a gasket on the ignition cover, it would need a drain for rain/water.

Earl

[quote="kz"]

In my opinion the hole must be a drain hole for the area behind the ignition cover; this also makes sense, because there is no gasket for the ignition cover.